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When we analyze the salt salinity (盐浓度) of ocean waters, we find that it varies only slightly from place to place． Nevertheless, some of these small changes are important． There are three basic processes that cause a change in oceanic salinity． One of these is the subtraction of water from the ocean by means of evaporation． In this manner, the salinity is increased, since the salt stays behind． If this is carried to the extreme, of course, white salt would be left behind ; this, by the way,is how much of the table salt we use is actually obtained．
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean． Here the ocean is being diluted so that the salinity is decreased． This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean． Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation．
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation． similarly, in coastal．
Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old．
So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I 'm busy, go watch television．
And watch TV they do; count them by the millions．
But it's usually not children's television that children watch． Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing．
Where are they to be found?Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch． That's where you find our kids, over five million of them, at 10 p．m．, not fewer than a million until after midnight! All of this is done with parental permission．
Television, used well, can provide enriching experiences for our young people, but we must use it with some sense． When the carpet is clean, we turn off the vacuum cleaner． When the dishes are clean, the dishwasher turns itself off．
Not so the television, which is on from the sun in the morning to the moon at night and beyond!
Parents must exercise some control and show some concern about the cultural influence on the child when a program not intended for that child is viewed． Parents need to intervene． Nonintervention may be a wise policy in international affairs, but the results of parental nonintervention will not be wise at alL．
The working parent is not willing to listen to her (his) four-year-old child talking about his sandbox games because she (he) is _____
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean． Here the ocean is being diluted so that the salinity is decreased． This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean． Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation．
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation． similarly, in coastal．
Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old．
So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I 'm busy, go watch television．
And watch TV they do; count them by the millions．
But it's usually not children's television that children watch． Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing．
Where are they to be found?Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch． That's where you find our kids, over five million of them, at 10 p．m．, not fewer than a million until after midnight! All of this is done with parental permission．
Television, used well, can provide enriching experiences for our young people, but we must use it with some sense． When the carpet is clean, we turn off the vacuum cleaner． When the dishes are clean, the dishwasher turns itself off．
Not so the television, which is on from the sun in the morning to the moon at night and beyond!
Parents must exercise some control and show some concern about the cultural influence on the child when a program not intended for that child is viewed． Parents need to intervene． Nonintervention may be a wise policy in international affairs, but the results of parental nonintervention will not be wise at alL．
The working parent is not willing to listen to her (his) four-year-old child talking about his sandbox games because she (he) is _____
A. boring
B. very tired
C. busy
D. angry
B. very tired
C. busy
D. angry
参考答案
参考解析
解析：根据第一段“0ne of these is the subtraction of water from the ocean by means of evaporation In this nlallner，the salinity is increased”可知，答案为C，即海水蒸发可使盐度增加。
更多 “When we analyze the salt salinity (盐浓度) of ocean waters, we find that it varies only slightly from place to place． Nevertheless, some of these small changes are important． There are three basic processes that cause a change in oceanic salinity． One of these is the subtraction of water from the ocean by means of evaporation． In this manner, the salinity is increased, since the salt stays behind． If this is carried to the extreme, of course, white salt would be left behind ; this, by the way,is how much of the table salt we use is actually obtained． The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean． Here the ocean is being diluted so that the salinity is decreased． This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean． Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation． Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation． similarly, in coastal． Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old． So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I 'm busy, go watch television． And watch TV they do; count them by the millions． But it's usually not children's television that children watch． Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing． Where are they to be found?Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch． That's where you find our kids, over five million of them, at 10 p．m．, not fewer than a million until after midnight! All of this is done with parental permission． Television, used well, can provide enriching experiences for our young people, but we must use it with some sense． When the carpet is clean, we turn off the vacuum cleaner． When the dishes are clean, the dishwasher turns itself off． Not so the television, which is on from the sun in the morning to the moon at night and beyond! Parents must exercise some control and show some concern about the cultural influence on the child when a program not intended for that child is viewed． Parents need to intervene． Nonintervention may be a wise policy in international affairs, but the results of parental nonintervention will not be wise at alL． The working parent is not willing to listen to her (his) four-year-old child talking about his sandbox games because she (he) is _____A. boring B. very tired C. busy D. angry” 相关考题
考题
阅读下面短文,根据短文内容,在短文后81－85小题中句子空白处填入适当的词语或句子。We know that m
阅读下面短文，根据短文内容，在短文后８１－８５小题中句子空白处填入适当的词语或句子。We know that many animals do not stay in one place. Birds, fish and other animals move from one place to another place at a certain time. They move for different reasons: most of them move to find food more easily, but others move to get away from places that are too crowded.When cold weather comes, many birds move to warmer places to find food. Some fishes give birth in warm water and move to cold water to feed. The most famous migration is probably the migration of fish, which is called “salmon”（鲑鱼）. This fish is born in fresh water but it travels many miles to salt water. There it spends its life. When it is old, it returns to its birthplace in fresh water. Then it gives birth and dies. In northern Europe, there is a kind of mouse. They leave their mountain homes when they become too crowded. They move down to the low land. Sometimes they move all the way to the seaside, and many of them are killed when they fall into the sea.Recently, scientists have studied the migration of a kind of lobster(龙虾). Every year, when the season of the bad weather arrives, the lobsters get into a long line and start to walk across the floor of the ocean. Nobody knows why they do this, and nobody knows where the go. So, sometimes we know why humans and animals move from one place to another place, but at other times we don’t. Maybe living things just like to travel.81. The reason for most of the animals to move is _____________________.
考题
BThree soldiers were on their way home from the war.They arrived at a small village,they were very tired and (51),but they had no food or money. The only thing they did have was a cooking pot(锅).The soldiers built a small cooking fire,(52) their pot on it,and poured in some water. When a few villagers asked what they were doing, one of the soldiers answered that he was making stone soup. A few more villagers walking by stopped to (53) what was goingon when they heard about it.“Any soup needs salt and pepper,”the first soldier said,(54) some children ran to fetch salt and pepper.“Stones can be used to prepare good soup,but tomatoes would (55) it so much better,” the second soldier added. One woman said“, Why,I think I have a tomato or two! ”She ran to get the tomatoes.“Some cabbage would be a proper choice for a good stone soup! ”said the third soldier. Another woman said,“I think I can probably find some cabbage,”and (56) she ran.“If only we had a bit of beef and some potatoes,this soup would be fit for a rich man's (57).”The villagers thought it over,then ran to fetch what they had in their homes. A rich man's soup,and all from a few stones! It seemed like (58)!The soldiers said“, If only we had a little milk,this soup would be fit for a king! ”And so other villagers (59) to get some milk.“The soup is ready,”said the cooks,“and all will (60) it,but first we need to set the tables.”Some of the villagers said,“Such a great soup would be better (61) some bread and cakes,”so they brought the (62) two things and the meal was (63) by all. Never had there been such a (64) meal. Never had the villagers had such delicious soup,and all made from stones! They ate and drank and danced well into the night.In the morning,the villagers gathered to say goodbye.“Many thanks to you,”they said,“for we shall (65) go hungry now that we have learned how to make soup from stones.”51.____________A.hungry B.bored C.sleepy D.sick
考题
BThe world is not only hungry，it is also thirsty for water． this may seem strange to you，since nearly 75% of the earth is covered with water． But about 97% of this water is sea water．Man can only drink and use the other 3% fresh water that comes from rivers，lakes，under-ground and other places． And we cannot even use all of that，because some of this fresh water has been made dirty．At the moment，this small amount(数量) of fresh water is still enough for us． However，our need for water is getting greater and greater． Only if we take steps to solve this problem now，we can get away from a serious world water shortage later on． The people of the world cannot have an enjoyable life without enough clean water．On one hand we should stop wasting this little water of ours，on the other hand we should find ways to reuse it，but this has not been done widely．Today，in most large cities，water is used only once and it then returns to the sea or runs into underground places．lf we can make it clean again，it can be used once more just as if it were fresh from a spring．But even if large cities reuse its water，we still would not have enough in the future． Where．could we turn to next for water? To the ocean! How can we do to make use of this great a-mount of sea water? We can take the salt from the water to make it fresh．So if we take all these steps，we'll be in no danger of drying up!( )26． Why does the writer say that the world is thirsty for water?A． The amount of fresh water is really very small．B． The people of the world waste too much water．C． The people of the world have to drink a lot of water every day．D． There are too many people in the world needing water．
考题
We still have________salt. We don't need_______salt now.
A、some. . . anyB、any. . . someC、a... someD、some. . . a
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
The purpose of mentioning the Weddell Sea is__________.
查看材料
A．to give an example of cold-water salinity
B．to point out the location of deep waters
C．to make a comparison between hot-water salinity and cold-water salinity
D．to show that the water in the Weddell Sea varies in salinity from place to place
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
Which of the following is not the cause of the decrease in the oceanic salinity?
查看材料A．Precipitation.
B．Rain and snow.
C．Formation of ice.
D．Addition of water by rivers.
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
It can be known from the passage that increase in the salinity of ocean water is caused by__________.
查看材料A．melting of sea ice
B．precipitation
C．evaporation
D．supplement of salt
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
Which of the following statements is TRUE according to the passage?
查看材料
A．Oceanic salinity has great effect on sea life.
B．Many factors combine to cause changes in oceanic salinity.
C．The movement of the water is related to the amount of salt.
D．The temperature of the water has much to do with the oceanic salinity.
考题
请阅读短文，完成此题。
When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of
high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.
This passage mainly tells us about__________.
查看材料A．the analysis of the salinity of ocean waters
B．the causes of the variation in oceanic salinity
C．the importance of the changes in oceanic salinity
D．the different forms of salts in ocean waters
考题
共用题干
Where Has the Salt Come from?Every now and then,we meet a fact about our earth that makes us feel strange and no answer for the fact has yet been found.Such a fact is the existence of salt in the oceans. How did it get there?We simply do not know how the salt got into the ocean!We do know,of course,that salt is water-soluble,and so passes into the oceans with rainwater.The salt of the earth's surface is constantly being dissolved（溶解）and is passing into the ocean.But we do not know whether this can explain the huge quantity of salt in oceans.If all the oceans were dried up,enough salt would be left to build a wall 180 miles high and a mile thick. Such a wall would reach once around the world at the Equator（赤道）!The common salt that we all use is produced from seawater or the water of salt lakes, from salt springs（源泉）and from deposits of rock salt. The concentration（浓度）of salt in seawater ranges from about three percent to three-and-one-half percent. The Dead Sea, which covers an area of about 340 square miles,contains about 11,600,000,000 tons of salt!On the average, a gallon（加仑）of seawater contains about a quarter of a pound of salt.The beds of rock salt that are found in various parts of the world were all originally formed by the evaporation（蒸发）of seawater millions of years ago. It is believed that the thick rock-salt deposits were formed after about nine-tenth of theY volume of seawater had been evaporated.Most commercial salt is obtained from rock salt.The usual method is to drill wells（井） down to the salt beds. Pure water is pumped down（抽进去）through a pipe. The water dissolves the salt and it is forced through another pipe up to the surface.A:Right B:Wrong C:Not mentioned
考题
共用题干
Where Has the Salt Come from?Every now and then,we meet a fact about our earth that makes us feel strange and no answer for the fact has yet been found.Such a fact is the existence of salt in the oceans. How did it get there?We simply do not know how the salt got into the ocean!We do know,of course,that salt is water-soluble,and so passes into the oceans with rainwater.The salt of the earth's surface is constantly being dissolved（溶解）and is passing into the ocean.But we do not know whether this can explain the huge quantity of salt in oceans.If all the oceans were dried up,enough salt would be left to build a wall 180 miles high and a mile thick. Such a wall would reach once around the world at the Equator（赤道）!The common salt that we all use is produced from seawater or the water of salt lakes, from salt springs（源泉）and from deposits of rock salt. The concentration（浓度）of salt in seawater ranges from about three percent to three-and-one-half percent. The Dead Sea, which covers an area of about 340 square miles,contains about 11,600,000,000 tons of salt!On the average, a gallon（加仑）of seawater contains about a quarter of a pound of salt.The beds of rock salt that are found in various parts of the world were all originally formed by the evaporation（蒸发）of seawater millions of years ago. It is believed that the thick rock-salt deposits were formed after about nine-tenth of theY volume of seawater had been evaporated.Most commercial salt is obtained from rock salt.The usual method is to drill wells（井） down to the salt beds. Pure water is pumped down（抽进去）through a pipe. The water dissolves the salt and it is forced through another pipe up to the surface.Beds of rock salt are found in every part of the world.A:Right B:Wrong C:Not mentioned
考题
共用题干
Where Has the Salt Come from?Every now and then,we meet a fact about our earth that makes us feel strange and no answer for the fact has yet been found.Such a fact is the existence of salt in the oceans. How did it get there?We simply do not know how the salt got into the ocean!We do know,of course,that salt is water-soluble,and so passes into the oceans with rainwater.The salt of the earth's surface is constantly being dissolved（溶解）and is passing into the ocean.But we do not know whether this can explain the huge quantity of salt in oceans.If all the oceans were dried up,enough salt would be left to build a wall 180 miles high and a mile thick. Such a wall would reach once around the world at the Equator（赤道）!The common salt that we all use is produced from seawater or the water of salt lakes, from salt springs（源泉）and from deposits of rock salt. The concentration（浓度）of salt in seawater ranges from about three percent to three-and-one-half percent. The Dead Sea, which covers an area of about 340 square miles,contains about 11,600,000,000 tons of salt!On the average, a gallon（加仑）of seawater contains about a quarter of a pound of salt.The beds of rock salt that are found in various parts of the world were all originally formed by the evaporation（蒸发）of seawater millions of years ago. It is believed that the thick rock-salt deposits were formed after about nine-tenth of theY volume of seawater had been evaporated.Most commercial salt is obtained from rock salt.The usual method is to drill wells（井） down to the salt beds. Pure water is pumped down（抽进去）through a pipe. The water dissolves the salt and it is forced through another pipe up to the surface.The author is sure that the dissolved salt from the earth's surface is the only source of the huge quantity of salt found in oceans.A:Right B:Wrong C:Not mentioned
考题
共用题干
Where Has the Salt Come from?Every now and then,we meet a fact about our earth that makes us feel strange and no answer for the fact has yet been found.Such a fact is the existence of salt in the oceans. How did it get there?We simply do not know how the salt got into the ocean!We do know,of course,that salt is water-soluble,and so passes into the oceans with rainwater.The salt of the earth's surface is constantly being dissolved（溶解）and is passing into the ocean.But we do not know whether this can explain the huge quantity of salt in oceans.If all the oceans were dried up,enough salt would be left to build a wall 180 miles high and a mile thick. Such a wall would reach once around the world at the Equator（赤道）!The common salt that we all use is produced from seawater or the water of salt lakes, from salt springs（源泉）and from deposits of rock salt. The concentration（浓度）of salt in seawater ranges from about three percent to three-and-one-half percent. The Dead Sea, which covers an area of about 340 square miles,contains about 11,600,000,000 tons of salt!On the average, a gallon（加仑）of seawater contains about a quarter of a pound of salt.The beds of rock salt that are found in various parts of the world were all originally formed by the evaporation（蒸发）of seawater millions of years ago. It is believed that the thick rock-salt deposits were formed after about nine-tenth of theY volume of seawater had been evaporated.Most commercial salt is obtained from rock salt.The usual method is to drill wells（井） down to the salt beds. Pure water is pumped down（抽进去）through a pipe. The water dissolves the salt and it is forced through another pipe up to the surface.We have not fully understood how salt got into the ocean.A:Right B:Wrong C:Not mentioned
考题
When we analyze the salt salinity (盐浓度) of ocean waters, we find that it varies only slightly from place to place． Nevertheless, some of these small changes are important． There are three basic processes that cause a change in oceanic salinity． One of these is the subtraction of water from the ocean by means of evaporation． In this manner, the salinity is increased, since the salt stays behind． If this is carried to the extreme, of course, white salt would be left behind ; this, by the way,is how much of the table salt we use is actually obtained．
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean． Here the ocean is being diluted so that the salinity is decreased． This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean． Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation．
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation． similarly, in coastal．
Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old．
So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I 'm busy, go watch television．
And watch TV they do; count them by the millions．
But it's usually not children's television that children watch． Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing．
Where are they to be found?Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch． That's where you find our kids, over five million of them, at 10 p．m．, not fewer than a million until after midnight! All of this is done with parental permission．
Television, used well, can provide enriching experiences for our young people, but we must use it with some sense． When the carpet is clean, we turn off the vacuum cleaner． When the dishes are clean, the dishwasher turns itself off．
Not so the television, which is on from the sun in the morning to the moon at night and beyond!
Parents must exercise some control and show some concern about the cultural influence on the child when a program not intended for that child is viewed． Parents need to intervene． Nonintervention may be a wise policy in international affairs, but the results of parental nonintervention will not be wise at alL．
From the first two paragraphs one may infer that the writer's attitude towards
"the old days" is ______A. preferring
B. hating
C. being tired of
D. disappointing
考题
It can be known from the passage that increase in the salinity of ocean water is caused by___________.A.melting of sea ice
B.precipitation
C.evaporation
D.supplement of salt
考题
根据下列内容，回答201-205题。
When we analyze the salt salinity(盐浓度) of ocean waters, we find that it varies only slightlyfrom place to place. Nevertheless, some of these small changes are important. There are three basicprocesses that cause a change in oceanic salinity. One of these is the subtraction of water from theocean by means of evaporation. In this manner, the salinity is increased, since the salt stays be-hind. If this is carried to the extreme, of course, white salt would be left behind; this, by the
way, is how much of the table salt we use is actually obtained.
The opposite of evaporation is precipitation, such as rain, by which water is added to theocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas ofhigh rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increasedby the subtraction of water by evaporation, or decreased by the addition of fresh water by precipi-tation.
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higherthan it is in other parts of the world where there is not as much evaporation. Similarly, in coastalregions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting ofsea ice. When seawater is frozen, the dissolved materials are left behind. In thismanner, seawaterdirectly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared.
Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing pro-cess, which increases the salinity of cold water. This heavy water sinks and is found in the deeperportion of the oceans of the world.
This passage mainly tells us about___________.A.the analysis of the salinity of ocean waters
B.the causes of the variation in oceanic salinity
C.the importance of the changes in oceanic salinity
D.the different forms of salts in ocean waters
考题
When we analyze the salt salinity (盐浓度) of ocean waters, we find that it varies only slightly from place to place． Nevertheless, some of these small changes are important． There are three basic processes that cause a change in oceanic salinity． One of these is the subtraction of water from the ocean by means of evaporation． In this manner, the salinity is increased, since the salt stays behind． If this is carried to the extreme, of course, white salt would be left behind ; this, by the way,is how much of the table salt we use is actually obtained．
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean． Here the ocean is being diluted so that the salinity is decreased． This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean． Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation．
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation． similarly, in coastal．
Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old．
So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I 'm busy, go watch television．
And watch TV they do; count them by the millions．
But it's usually not children's television that children watch． Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing．
Where are they to be found?Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch． That's where you find our kids, over five million of them, at 10 p．m．, not fewer than a million until after midnight! All of this is done with parental permission．
Television, used well, can provide enriching experiences for our young people, but we must use it with some sense． When the carpet is clean, we turn off the vacuum cleaner． When the dishes are clean, the dishwasher turns itself off．
Not so the television, which is on from the sun in the morning to the moon at night and beyond!
Parents must exercise some control and show some concern about the cultural influence on the child when a program not intended for that child is viewed． Parents need to intervene． Nonintervention may be a wise policy in international affairs, but the results of parental nonintervention will not be wise at alL．
What is the main idea of the last paragraph?A. Parental nonintervention will not be praised．
B. Nonintervention may be a good policy in international affairs．
C. Parents must exercise some control and show some concern about the cultural influence on the children．
D. Parents need to intervene．
考题
When we analyze the salt salinity (盐浓度) of ocean waters, we find that it varies only slightly from place to place． Nevertheless, some of these small changes are important． There are three basic processes that cause a change in oceanic salinity． One of these is the subtraction of water from the ocean by means of evaporation． In this manner, the salinity is increased, since the salt stays behind． If this is carried to the extreme, of course, white salt would be left behind ; this, by the way,is how much of the table salt we use is actually obtained．
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean． Here the ocean is being diluted so that the salinity is decreased． This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean． Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation．
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation． similarly, in coastal．
Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old．
So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I 'm busy, go watch television．
And watch TV they do; count them by the millions．
But it's usually not children's television that children watch． Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing．
Where are they to be found?Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch． That's where you find our kids, over five million of them, at 10 p．m．, not fewer than a million until after midnight! All of this is done with parental permission．
Television, used well, can provide enriching experiences for our young people, but we must use it with some sense． When the carpet is clean, we turn off the vacuum cleaner． When the dishes are clean, the dishwasher turns itself off．
Not so the television, which is on from the sun in the morning to the moon at night and beyond!
Parents must exercise some control and show some concern about the cultural influence on the child when a program not intended for that child is viewed． Parents need to intervene． Nonintervention may be a wise policy in international affairs, but the results of parental nonintervention will not be wise at alL．
According to the writer, the responsibility for the kid's watching adult television and watching it for a long time should be undertaken by _____A. the television stations
B. the society
C. TV programs
D. their parents
考题
The purpose of mentioning the Weddell Sea is___________.A.to give an example of cold-water salinity
B.to point out the location of deep waters
C.to make a comparison between hot-water salinity and cold-water salinity
D.to show that the water in the Weddell Sea varies in salinity from place to place
考题
When we analyze the salt salinity (盐浓度) of ocean waters, we find that it varies only slightly from place to place． Nevertheless, some of these small changes are important． There are three basic processes that cause a change in oceanic salinity． One of these is the subtraction of water from the ocean by means of evaporation． In this manner, the salinity is increased, since the salt stays behind． If this is carried to the extreme, of course, white salt would be left behind ; this, by the way,is how much of the table salt we use is actually obtained．
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean． Here the ocean is being diluted so that the salinity is decreased． This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean． Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation．
Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation． similarly, in coastal．
Grandma, who used to live upstairs, is now the voice on long distance, and the working parent is far too beaten down each day to spend evening relaxation time listening to the sandbox experience of an eager four-year-old．
So family conversation is as extinct as my old toys and parental questions such as "What have you been doing, Bobby? " have been replaced by "I 'm busy, go watch television．
And watch TV they do; count them by the millions．
But it's usually not children's television that children watch． Saturday morning, the children's hour, amounts to only about 8 percent of their weekly viewing．
Where are they to be found?Watching adult television, of course, from the Match Game in the morning, to the afternoon at General Hospital, from the muggings and battles on the evening news right through the family hour and past into Starsky and Hutch． That's where you find our kids, over five million of them, at 10 p．m．, not fewer than a million until after midnight! All of this is done with parental permission．
Television, used well, can provide enriching experiences for our young people, but we must use it with some sense． When the carpet is clean, we turn off the vacuum cleaner． When the dishes are clean, the dishwasher turns itself off．
Not so the television, which is on from the sun in the morning to the moon at night and beyond!
Parents must exercise some control and show some concern about the cultural influence on the child when a program not intended for that child is viewed． Parents need to intervene． Nonintervention may be a wise policy in international affairs, but the results of parental nonintervention will not be wise at alL．
If we use television with some _______, television can provide our young people with much knowledge．A. instruction of experts
B. judgment of our own
C. direction of engineers
D. indication of teachers
考题
资料：When we see well，we do not think about our eyes very often. It is only when we cannot see perfectly that we realize how important our eyes are.
People who are near-sighted can only see things that are very close to their eyes，Everything else seems blurry（=unclear）.Many people who do a lot of work，such as writing，reading and sewing become near-sighted.
People who are far-sighted suffer from just the opposite problem. They can see things that are far away，but they have difficulty in reading a book unless they hold it at arm’s length. If they want to do much reading，they must get glasses，too.
Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism. This，too，can be corrected by glasses. Some people’s eyes become cloudy because of cataracts. Long ago these people often became blind. Now，however，it is possible to operate on the cataracts and remove them.
Having two good eyes is important for judging distances. Each eye sees things from a slightly different angle. To prove this to yourself，look at an object out of one eye；Then look at the same object out of your other eye. You will find the object’s relation to the background and other things around it has changed. The difference between these two different eye views helps us to judge how far away an object is. People who have only one eye cannot judge distance as people with two eyes.
We should take good care of our eyes______.
A.even if we can see well
B.only when we cannot see perfectly
C.only when we realize how important our eyes are
D.only when we can see well
考题
共用题干
What We Take From and Give to the SeaAs long as we have been on earth,we have used the sea around us.We take from the ocean,and we give to it.We take fishes from the ocean-millions of kilograms of fish,every year,to________(51)millions of people.We even_______(52)their bones for fertilizer.We take minerals from the ocean.One way to get salt is to_______(53)seawater in shallow basin and leave it until it evaporates（蒸发）.Along with salt,other minerals are left_______(54)evaporation.Much gold and silver drift dissolved in the waters of the sea,too.But the sea does not give them_______(55)by simple evaporation.________(56)gifts from the sea are pearls , sponges（海绵）and seaweed.Pearls________(57)jewelry.Natural sponges become cleaning aids.Seaweed becomes______(58)of many kinds一even candy,and ice cream一as well as medicine.Believe it or not,fresh water is another_______(59)from the sea.We cannot drink ocean water.Some of its contents may______(60)illness.But ocean water becomes fresh water when the salts are ________(61).In the future,we will find ourselves．________(62)more and more onfresh water from the sea.The sea_______(63)us food,fertilizer,minerals,water,and other gifts.What do we give the sea?Garbage.We pollute the ocean_______(64)we use it as a garbage dump.Huge as it is,the ocean cannot hold all the water that we pour into it.________(65)garbage into the ocean is killing off sea life.Yet as the world population grows,we may need the sea and its gifts more than ever._________65A:Reducing B:Collecting C:Removing D:Casting
考题
共用题干
What We Take From and Give to the SeaAs long as we have been on earth,we have used the sea around us.We take things from the ocean,and we give to it.We take fishes from the ocean-millions of kilograms of fish,every year,to feed millions of people.______(46)We take minerals from the ocean.One way to get salt is to place seawater in a shallow basin and leave it until it evaporates.______(47) Much gold and silver drift dissolved in the waters of the sea,too.But the sea does not give them up by simple evaporation.Other gifts from the sea are pearls,sponges and seaweed.Pearls become jewelry.______(48)Seaweed becomes food of many kinds-even candy,and ice cream-as well as medicine.Believe it or not,fresh water is another gift from the sea.We cannot drink ocean water.______(49)But ocean water becomes fresh water when the salts are removed.In the future,we will find ourselves depending more and more on fresh water from the sea.The sea gives us food,fertilizer,minerals,water,and other gifts .What do we give the sea?Garbage.______(50)Huge as it is,the ocean cannot hold all the water we pour into it. Dumping garbage into the ocean is killing off sea life.Yet as the world population grows,we may need the sea and its gifts more than ever.We are finally learning that if we destroy our sea,we might also destroy ourselves.Hopeful-ly,it is not too late.______(48)A: Natural sponges become cleaning aids.B: We pollute the ocean when we use it as a garbage dump.C: The area of the sea is becoming smaller and smaller.D: Along with salt,other minerals are left after evaporation.E: We even use their bones for fertilizer.F: Some of its contents may cause illness.
考题
Very few of our birds stay with us the year round.Some come to us in the winter from the cold?north.Others come from the south to spend the summer with us.How do they know the way?Suppose?you were told to find your way to a place hundreds of miles away,do you think you could do it?
Yet birds travel over mountains,forests,lakes and even across the oceans,and do not stray from?the path.They find their way back in the spring to the same orchard（果园）and the very trees where?they nested the summer before.
It is wonderful how quickly birds travel such long distances from their summer homes to their?winter ones.Some birds have been known to fly hundreds of miles in a day.But others travel much?more slowly.
Why do birds undertake these long journeys twice a year?Perhaps cold weather and lack of?food drive them from us in the autumn,but we cannot tell why they leave the sunny south to come?back to us in the spring.We know only that many of them like to make their nests and rear their?young in the north.
We are sorry to see them go,but we know that when winter is over they will come back to us.
In which season do we have most birds to stay with us?A.In spring.
B.In summer.
C.In winter.
D.We don't know.
考题
Very few of our birds stay with us the year round.Some come to us in the winter from the cold?north.Others come from the south to spend the summer with us.How do they know the way?Suppose?you were told to find your way to a place hundreds of miles away,do you think you could do it?
Yet birds travel over mountains,forests,lakes and even across the oceans,and do not stray from?the path.They find their way back in the spring to the same orchard（果园）and the very trees where?they nested the summer before.
It is wonderful how quickly birds travel such long distances from their summer homes to their?winter ones.Some birds have been known to fly hundreds of miles in a day.But others travel much?more slowly.
Why do birds undertake these long journeys twice a year?Perhaps cold weather and lack of?food drive them from us in the autumn,but we cannot tell why they leave the sunny south to come?back to us in the spring.We know only that many of them like to make their nests and rear their?young in the north.
We are sorry to see them go,but we know that when winter is over they will come back to us.
The underlined part"stray from the path"means__________.A.lose its way
B.stay on the path
C.keep away from the path
D.fly along the path
考题
单选题We can NOT conclude that the accelerometers ______.A
are bound into three pairsB
are able to sense fantastically small disturbancesC
keep the satellite stable and prevent it from falling out of the skyD
contain some very fragile mechanisms
考题
问答题Practice 5 The world's oceans are slowly getting more acidic, say scientists. The researchers from California say the change is taking place in response to higher levels of carbon dioxide in the atmosphere. The lowering of the waters' pH value is not great at the moment but could pose a serious threat to current marine life if it continues, they warn. Ken Caldeira and Michael Wickett, from the Lawrence Livermore National Laboratory, report their concerns in the journal Nature. Increasing use of fossil fuels means more carbon dioxide is going into the air, and most of it will eventually be absorbed by seawater. Once in the water, it reacts to form carbonic acid. Scientists believe that the oceans have already become slightly more acidic over the last century. But these researchers have tried to predict what will happen in the future by combining what we know about the history of the oceans with computer models of climate change. "This level of acidity will get much more extreme in the future if we continue releasing CO2 into the atmosphere," said Dr Caldeira. "And we predicted amounts of future acidity that exceed anything we saw over the last several hundred million years, apart from perhaps after rare catastrophic events such as asteroid impacts." If carbon dioxide release continues unabated, ocean pH could be reduced by as much as 0.77 units, the authors warn. It is not absolutely clear what that means for marine life, however. Most organisms live near the surface, where the greatest pH change would be expected to occur, but deep-ocean lifeforms may be more sensitive to pH changes. Coral reefs and other organisms whose skeletons or shells contain calcium carbonate may be particularly affected, the team speculate. They could find it much more difficult to build these structures in water with a lower pH. In recent years some people have suggested deliberately storing carbon dioxide from power stations in the deep ocean as a way of curbing global warming. But Dr Caldeira said that such a strategy should now be re-considered. "Previously, most experts had looked at ocean absorption of carbon dioxide as a good thing — because in releasing CO2 into the atmosphere we warm the planet; and when CO2 is absorbed by the ocean, it reduces the amount of greenhouse warming.
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