网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
We drop a piece of metal into a jar full of water, the metal will float if it weighs less than______.
A. an equal amount of silver
B. an equal amount of gold
C. all the water in the jar now
D. the water that leaves the jar
参考答案
更多 “ We drop a piece of metal into a jar full of water, the metal will float if it weighs less than______.A. an equal amount of silverB. an equal amount of goldC. all the water in the jar nowD. the water that leaves the jar ” 相关考题
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
Passage FourArchimedes was a famous Greek mathematician and scientist. He was born around 287 BC and he died in the year 212 BC.Archimedes is most well-known for one specific idea that he came up with. "Archimedes's Principle" states that a solid object which is immersed in a liquid is pushed up by a force which is equal to the weight of the water that the object moves. For example, if you put a piece of wood and a piece of gold the same size in water, only the wood will float. Both the wood and gold move the same amount of water, but the wood weighs less than this water, while the gold weighs more.It is believed that Archimedes discovered this principle when the king of Syracuse asked him to solve a problem. The king wanted to know if his crown was pure gold or a mixture of gold and silver. The king, of course, did not melt his crown to find out. The idea came to Archimedes as he lowered himself into his bath. He noticed how the water spilled out of the tub. He decided to use the same idea for the crown. He knew that a gold crown immersed in water would weigh more than one made of silver. The experiment was done and the goldsmith was proved guilty of trying to cheat the king.48. A good title for the selection is______.A. ArchimedesB. Archimedes's PrincipleC. A Gold and Silver CrownD. The King of Syracuse
考题
Magnesium has a specific gravity of 1.74, which means that ___ 1.74 times as much as an equal volume of water.
A、it is weighedB、weighing itC、its weightD、it weighs
考题
One advantage of the all-purpose nozzle is that it ______.A.can fit any size hoseB.converts a stream of water into a fogC.increases the amount of water reaching the fireD.can spray two streams of water at the same time
考题
A developer is creating a class Book that needs to access class Paper.The Paper class is deployed in a JARnamedmyLib.jar.Whichthree，taken independently，will allow the developer to use the Paper class while compiling the Book class？（）A.The JAR fileis located at$JAVA_HOME/jre/classes/myLib.jar.B.The JAR fileis located at$JAVA_HOME/jre/lib/ext/myLib.jar.C.TheJ AR fileis located at/foo/myLib.jar and aclasspath environment variable is set that includes /foo/myLib.jar/Paper.class.D.The JAR fileis located at/foo/myLib.jar and a classpath environment variable is set that includes/foo/myLib.jar.E.The JAR file is located at/foo/myLib.jar and the Book class is compiled using javac-cp/foo/myLib.jar/Paper Book.java.F.The JAR file is located at/foo/myLib.jar and the Book class is compiled using javac-classpath/foo/myLib.jar Book.java.
考题
The water level showing in a boiler water gauge glass is usually ( ) duringworking.A.higher than the actual drum water levelB.equal to the actual drum water levelC.increasing due to steam condensation in the glassD.lower than actual drum wafer level
考题
When the prime movers of two paralleled generators are equipped with mechanical-hydraulic governors, and are operating within their designed range, the unit with the least amount of speed droop will .A.pick up more of any increase in loadB.pick up less of any increase in loadC.share an equal amount of any increase in loadD.drop an equal amount of any decrease in load
考题
One day，a teacher was speaking to a group of students about how to (31) their time．He gave an example those students would never forget．He pulled out a wide jar(罐子) and put it on the table． He also took out several rocks and carefully put them into the jar one at a time． When no more rocks would( 32) inside，he asked，"Is this jar full?"Everyone in the class shouted，" Yes． "The teacher replied，"Really?" He pulled out a box of small stones． He dumped some in and ) (33)the jar． The stones went down into the spaces (34) the big rocks． He then asked the group once more，"Is this jar full?""Probably not，"one of them answered． "Good ! "he replied． He brought out a glass of sand and dumped the sand into the jar and it went into all of the spaces( 35) ． Once more he asked the question，"Is this jar full?""No!"the class shouted． Once again he said，"Good! Then he poured a cup of water in (36) the．jar was full． Then he asked，"What is the key point here?"One student put up his hand and said，"The key point here is that even if you are busy，you can (37) plan everything well if you try really hard ! "" No， the speaker replied，"that's not the point． The point is if you don-t put the big rocks In(38) ，your ’ll never get them in． What are the 'big rocks in your (39) ? Time with your loved ones，your education，or your dreams? Remember to put these big rocks in first，or you ’II never get them in (40) ．"( )31．A．spendB．takeC．killD．arrange
考题
共用题干
The Drink Your Body Needs Most1. Our bodies are estimated to be about 60%to 70%water. Blood is mostly water, and our mus- dles,lungs and brain all contain a lot of water. Water is needed to regulate body temperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxy-gen to our cells,removes waste,and protects our joints and organs.2. We lose water through urination（排尿）, respiration（呼吸）, and by sweating. If you are very active,you lose more water than if you do not take much exercise.Symptoms of mild dehydration （脱水）include chronic pains in joints and muscles,lower back pain,headaches,and constipation（便秘）.A strong smell to your urine,along with a yellow color indicates that you are not getting enough water. Thirst is an obvious sign of dehydration and in fact,you need water long before you feel thirsty.3 .A good rule of thumb（好的做法）is to take your body weight in pounds and divide that num- her in half. That gives you the number of ounces（盎司）of water per day that you need.For ex-ample,if you weigh 160 pounds,you should drink at least 80 ounces of water per day.If you ex- ercise you should drink another 8-ounce glass of water for every 20 minutes you are active.If you drink coffee or alcohol,you should add at least an equal amount of water. When you are traveling on an airplane,it is good to have 8 ounces of water for every hour you are on board the plane.4 .It may be difficult to drink enough water on a busy day.Be sure you have water handy at all times by keeping a bottle for water with you when you are working,traveling,or exercising. If you get bored with plain water,add a bit of lemon for a touch of flavor. There are some brands of fla-vored water available,but some of them have sugar or artificial sweeteners that you don't need. The amount of water your body needs per day is related_________.A: in your bodyB: without waterC: before longD: for a changeE: on a busy dayF: to your weight
考题
共用题干
The Drink Your Body Needs Most1 Our bodies are estimated to be about 60% to 70% water.Blood is mostly water,and our muscles,lungs,and brain all contain a lot of water.Water is needed to regulate body temperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxygen to our cells,removes waste,and protects our joints and organs.2 We lose water through urination（排尿）,respiration（呼吸）,and by sweating. If you are very active,you lose more water than if you do not take much exercise.Symptoms of mild dehydration（脱水）include chronic pains in joints and muscles , lower back pain, headaches, and constipation（便秘）.A strong smell to your urine , along with a yellow color indicates that you are not getting enough water.Thirst is an obvious sign of dehydration and in fact,you need water long before you feel thirsty.3 A good rule of thumb（好的做法）is to take your body weight in pounds and divide that number in half. That gives you the number of ounces（盎司）of water per day that you need.For example,if you weigh 160 pounds,you should drink at least 80 ounces of water per day.If you exercise you should drink another 8-ounce glass of water for every 20 minutes you are active.If you drink coffee or alcohol,you should add at least an equal amount of water.When you are traveling on an airpiane,it is good to have 8 ounces of water for every hour you are on board the plane.4 It may be difficult to drink enough water on a busy day.Be sure you have water handy at all times by keeping a bottle for water with you when you are working,traveling,or exercising.If you get bored with plain water,add a bit of lemon for a touch of flavor.There are some brands of flavored water available,but some of them have sugar or artificialsweeteners that you don't need. One cannot live_______.A:in your bodyB:without waterC:before longD:for a changeE:on a busy dayF:to your weight
考题
A developer is creating a class Book, that needs to access class Paper. The Paper class is deployed in a JAR named myLib.jar. Which three, taken independently, will allow the developer to use the Paper class while compiling the Book class?（）A、The JAR file is located at $JAVA_HOME/jre/classes/myLib.jar.B、The JAR file is located at $JAVA_HOME/jre/lib/ext/myLib.jar..C、The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes /foo/myLib.jar/Paper.class.D、The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes /foo/myLib.jar.E、The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac -cp /foo/myLib.jar/Paper Book.java.F、The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac -d /foo/myLib.jar Book.javaG、The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac -classpath /foo/myLib.jar Book.java
考题
A developer is creating a class Book， that needs to access class Paper. The Paper class is deployed in a JAR named myLib.jar. Which three， taken independently， will allow the developer to use the Paper class while compiling the Bookclass？（）A、The JAR file is located at $JAVA_HOME/jre/classes/myLib.jar.B、The JAR file is located at $JAVA_HOME/jre/lib/ext/myLib.jar..C、The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes /foo/myLib.jar/Paper.class.D、The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes /foo/myLib.jar.E、The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - cp /foo/myLib.jar/Paper Book.java.F、The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - classpath /foo/myLib.jar Book.java
考题
单选题Which would you NOT use to report the amount of anchor chain out? Three shots（）.A
at the water's edgeB
on deckC
on the bottomD
well in the water
考题
多选题A developer is creating a class Book， that needs to access class Paper. The Paper class is deployed in a JAR named myLib.jar. Which three， taken independently， will allow the developer to use the Paper class while compiling the Bookclass？（）AThe JAR file is located at $JAVA_HOME/jre/classes/myLib.jar.BThe JAR file is located at $JAVA_HOME/jre/lib/ext/myLib.jar..CThe JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes /foo/myLib.jar/Paper.class.DThe JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes /foo/myLib.jar.EThe JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - cp /foo/myLib.jar/Paper Book.java.FThe JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - classpath /foo/myLib.jar Book.java
考题
单选题When distilling salt water the cooling water discharging from the distiller is fed back to evaporator as feed water （）.A
to cut down the amount of cooling water neededB
to prevent an excess amount of cooling water from being discharged to the bilgesC
to supply hot water to the evaporator for more economical operationD
None of the above is tree
考题
单选题The rate of heat transfer in a water-tube auxiliary boiler can be increased by （）.A
operating the boiler at less than normal water levelB
installing fins on the firesides of water-tubesC
increasing the amount of excess air to the burnersD
treating the boiler water with chemical oxygen scavengers
考题
单选题Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to （）A
maintain low pH in the cooling waterB
reduce the cooling water temperatureC
increase cooling water hardnessD
form a protective film on metal surfaces
考题
单选题Fog forms when the air（）.A
Is 50% water saturatedB
Is 90% water saturatedC
Temperature is greater than the dew point temperatureD
Temperature is equal to，or below the dew point temperature
考题
单选题When the prime movers of two paralleled generators are equipped with mechanical- hydraulic governors, and are operating within their designed range, the unit with the least amount of speed droop will （）.A
pick up more of any increase in loadB
pick up less of any increase in loadC
share an equal amount of any increase in loadD
drop an equal amount of any decrease in load
考题
单选题Allowance for fresh water refers to（）.A
the provision to be provided when the vessel sails in fresh water areaB
the fresh water to be carried by a vesselC
the allowance of fresh water for each crew member when in distress at seaD
the amount of free board decreased when sailing in fresh water area
考题
单选题Higher than normal jacket water temperatures occurring in all cylinders of a diesel engine can result from a/an （）.A
oil suction line restrictionB
correct amount of coolantC
cavitation erosion in the water jacketsD
clogged sea suction strainer
考题
单选题One advantage of the all-purpose nozzle is that it（）.A
can fit any size hoseB
converts a stream of water into a fogC
increases the amount of water reaching the fireD
can spray two streams of water at the same time
考题
单选题When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.A
increase the amount of cooling water to the condenserB
decrease the amount of cooling water to the condenserC
add more refrigerant to the systemD
remove some refrigerant from the system
考题
单选题If the compressor-discharge temperature is higher than the receiver temperature（）A
increase the amount of cooling water to the condenserB
decrease the amount of cooling water to the condenserC
add more refrigerant to the systemD
remove some of the refrigerant from the system
考题
单选题The cooling water jacket is common to all the cylinders but there are often （） to ensure that each cylinder receives the right amount and flow of water.A
dividing wallsB
divided wallsC
dividing linersD
divided jackets
考题
单选题What is the normal length of anchor cable used to anchor a vessel?（）A
An amount equal to the depth of the waterB
Two times the depth of waterC
Three to four times the depth of waterD
Five to seven times the depth of water
热门标签
最新试卷
