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单选题
Which of the following is NOT true about elephants?
A
Usually elephants die at age of 60-70.
B
The female Asian elephants do not carry tusks.
C
Most mature elephants with good ivory are killed illegally.
D
Elephants are killed for ivory and meat.
参考答案
参考解析
解析：
录音中提到“Although elephants can live for up to 60-70 years, with the threat from ivory poaching few mature elephants with good ivory reach this age.”(尽管大象可以生活长达60-70年，但是由于象牙偷猎活动的威胁有良好象牙的成年大象很少达到这一年龄)，所以C项正确，但是由此不能推断出通常大象都在60-70岁时死去，故A项错误。根据录音可知，雄性和雌性非洲象都有象牙，但是只有雄性的亚洲象有象牙，由此可知，雌性亚洲象没有象牙，所以B项正确。根据“Elephants are also being killed for their meat”可知，D项也正确。
录音中提到“Although elephants can live for up to 60-70 years, with the threat from ivory poaching few mature elephants with good ivory reach this age.”(尽管大象可以生活长达60-70年，但是由于象牙偷猎活动的威胁有良好象牙的成年大象很少达到这一年龄)，所以C项正确，但是由此不能推断出通常大象都在60-70岁时死去，故A项错误。根据录音可知，雄性和雌性非洲象都有象牙，但是只有雄性的亚洲象有象牙，由此可知，雌性亚洲象没有象牙，所以B项正确。根据“Elephants are also being killed for their meat”可知，D项也正确。
更多 “单选题Which of the following is NOT true about elephants?A Usually elephants die at age of 60-70.B The female Asian elephants do not carry tusks.C Most mature elephants with good ivory are killed illegally.D Elephants are killed for ivory and meat.” 相关考题
考题
Which of the following about the African bush elephant and the African elephant is true?A．The WCU are interbreeding those elephants.B．They are interbreeding species.C．They are two genetically distant species.D．They depend on each other for survival.
考题
Passage FourHave you ever heard of a flower whose seeds are carried and spread by elephants? The rafflesia, a rare blossom, is very unusual. Found in the rain forests of Sumatra, the rafflesia is the world's largest flower, measuring three feet in diameter!This giant flower is a parasite--it needs another plant to live on. It lacks the structures needed to survive alone. The rafflesia has no stem or leaves. It is all flower. It attaches itself to the roots of other plants and sucks their juices. The flower's favorite home is the root of the vine, which grows above ground.The rafflesia seems to burst right out of the forest floor. Its blossom weighs fifteen pounds! It has thick, spotted petals that give off a rotten smell. The center is about the size of a household bucket. After a rain, it may hold up to twelve pints of water!After the rafflesia dies, it becomes a pool of thick liquid in which its seeds float. Elephants wandering through the forest step into the mushy pool, and the seeds glue themselves to their feet. As the animals stomp through the forest, their sticky feet pick up twigs and leaves. The elephants try to rid themselves of the sticky mess, in the same way people try to get bubble gum off their shoes. The elephants rub their feet against the roots of the vine. In no time, seeds left on the vine grow into more monstrous flowers!48. Elephants help to ______.A. provide food for the giant flowerB. water the rafflesia with their trunksC. carry rafflesia seeds from one place to anotherD. stomp out the awful smelling petals
考题
Elephants would( )if men were allowed to shoot as many as they wished.A. die downB．die outC．die awayD．die off
考题
请阅读Passage 1。完成第小题。
Passage 1
African elephants have been slaughtered at alarming rate over the past decade, largely because they are the primary source of the world's ivory. Their population has been dwindled from 1.3 million in 1979 to just 625,000 today, and the rate of killing has been accelerating in recent years because many of the older, bigger tusked animals have already been destroyed. "The poachers now must kill times as many elephants to get the same quantity of ivory," explained Curtis Bohlen,Senior vice president of the World Wildlife Fund.
Though its record on the environment has been spotty so far, the government last week took the lead in a major conservation issue by imposing a ban on ivory imports into the US. The move came just four days after a consortium of conservation groups, including the World Wildlife Fund and Wildlife Conservation International, called for that kind of action, and it made the US the first nation to forbid imports of both raw and finished ivory. The ban, says Bohlen, sends a very clear message to the ivory poachers that the game is over.
In the past African nations have resisted an ivory ban, but increasingly they realized that the decimation of the elephant herds poses a serious threat to their tourist business. Last month Tanzania and several other African countries called for an amendment to the 102 nation Convention on International Trade in Endangered Species that would make the ivory trade illegal worldwide.
The amendment is expected to be approved at an October meeting in Geneva and to go into effect next January. But between now and then, conservationists contend, poachers may go on a rampage,killing elephants wholesale, so nations should unilaterally forbid imports right away. The US government brought that argument, and by week's end the twelve nations European Community had followed with its own ban.
According to the passage, "dwindle" (Para.1) means__________.
查看材料
A．decrease
B．enlarge
C．weaken
D．eliminate
考题
请阅读Passage 1。完成第小题。
Passage 1
African elephants have been slaughtered at alarming rate over the past decade, largely because they are the primary source of the world's ivory. Their population has been dwindled from 1.3 million in 1979 to just 625,000 today, and the rate of killing has been accelerating in recent years because many of the older, bigger tusked animals have already been destroyed. "The poachers now must kill times as many elephants to get the same quantity of ivory," explained Curtis Bohlen,Senior vice president of the World Wildlife Fund.
Though its record on the environment has been spotty so far, the government last week took the lead in a major conservation issue by imposing a ban on ivory imports into the US. The move came just four days after a consortium of conservation groups, including the World Wildlife Fund and Wildlife Conservation International, called for that kind of action, and it made the US the first nation to forbid imports of both raw and finished ivory. The ban, says Bohlen, sends a very clear message to the ivory poachers that the game is over.
In the past African nations have resisted an ivory ban, but increasingly they realized that the decimation of the elephant herds poses a serious threat to their tourist business. Last month Tanzania and several other African countries called for an amendment to the 102 nation Convention on International Trade in Endangered Species that would make the ivory trade illegal worldwide.
The amendment is expected to be approved at an October meeting in Geneva and to go into effect next January. But between now and then, conservationists contend, poachers may go on a rampage,killing elephants wholesale, so nations should unilaterally forbid imports right away. The US government brought that argument, and by week's end the twelve nations European Community had followed with its own ban.
Why did the African nations welcome an ivory ban?
查看材料
A．The rate of killing has been accelerating.
B．The US government forbids imports of both raw and finished ivory.
C．They realized that the killing of elephants is a serious threat to their tourist business.
D．African people advocated an ivory ban.
考题
请阅读Passage 1。完成第小题。
Passage 1
African elephants have been slaughtered at alarming rate over the past decade, largely because they are the primary source of the world's ivory. Their population has been dwindled from 1.3 million in 1979 to just 625,000 today, and the rate of killing has been accelerating in recent years because many of the older, bigger tusked animals have already been destroyed. "The poachers now must kill times as many elephants to get the same quantity of ivory," explained Curtis Bohlen,Senior vice president of the World Wildlife Fund.
Though its record on the environment has been spotty so far, the government last week took the lead in a major conservation issue by imposing a ban on ivory imports into the US. The move came just four days after a consortium of conservation groups, including the World Wildlife Fund and Wildlife Conservation International, called for that kind of action, and it made the US the first nation to forbid imports of both raw and finished ivory. The ban, says Bohlen, sends a very clear message to the ivory poachers that the game is over.
In the past African nations have resisted an ivory ban, but increasingly they realized that the decimation of the elephant herds poses a serious threat to their tourist business. Last month Tanzania and several other African countries called for an amendment to the 102 nation Convention on International Trade in Endangered Species that would make the ivory trade illegal worldwide.
The amendment is expected to be approved at an October meeting in Geneva and to go into effect next January. But between now and then, conservationists contend, poachers may go on a rampage,killing elephants wholesale, so nations should unilaterally forbid imports right away. The US government brought that argument, and by week's end the twelve nations European Community had followed with its own ban.
Since many of the older, bigger-tusked animals have already been destroyed, what did the poacher do?
查看材料
A．They gave up poaching.
B．They killed more elephants to get the same quantity of ivory..
C．To them, game is over.
D．They realized it was illegal to slaughter elephants.
考题
请阅读Passage 1。完成第小题。
Passage 1
African elephants have been slaughtered at alarming rate over the past decade, largely because they are the primary source of the world's ivory. Their population has been dwindled from 1.3 million in 1979 to just 625,000 today, and the rate of killing has been accelerating in recent years because many of the older, bigger tusked animals have already been destroyed. "The poachers now must kill times as many elephants to get the same quantity of ivory," explained Curtis Bohlen,Senior vice president of the World Wildlife Fund.
Though its record on the environment has been spotty so far, the government last week took the lead in a major conservation issue by imposing a ban on ivory imports into the US. The move came just four days after a consortium of conservation groups, including the World Wildlife Fund and Wildlife Conservation International, called for that kind of action, and it made the US the first nation to forbid imports of both raw and finished ivory. The ban, says Bohlen, sends a very clear message to the ivory poachers that the game is over.
In the past African nations have resisted an ivory ban, but increasingly they realized that the decimation of the elephant herds poses a serious threat to their tourist business. Last month Tanzania and several other African countries called for an amendment to the 102 nation Convention on International Trade in Endangered Species that would make the ivory trade illegal worldwide.
The amendment is expected to be approved at an October meeting in Geneva and to go into effect next January. But between now and then, conservationists contend, poachers may go on a rampage,killing elephants wholesale, so nations should unilaterally forbid imports right away. The US government brought that argument, and by week's end the twelve nations European Community had followed with its own ban.
Which of the following is the best title for the passage?
查看材料
A．African Elephants and the Ivory Trade
B．A Bid to Save the Elephant
C．The Poachers
D．Elephants in Danger
考题
共用题干
第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.Unlike other animals in zoos,zoo-raised elephantsA:live a long lifeB:give birth to many babiesC:develop poor healthD:have difficulty getting food
考题
共用题干
第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.Which of the following about the scientists'study is NOT true?A:They compared zoo-born elephants with wild elephants.B:They analyzed the records of 800 elephants kept in zoos.C:The zoo-born elephants they studied were kept in European zoos.D:They kept detailed records of all the elephants in their care.
考题
共用题干
第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.It was found that,compared with female wild elephants,female zoo-born elephants_______________.A:lived longerB:grew up fasterC:died much earlierD:enjoyed the same life spans
考题
共用题干
第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.It can be inferred from the last paragraph that______________.A:zoo-born elephants should be looked after more carefullyB:zoos should keep more animals except elephantsC:it may not be wise to keep elephants in zoosD:elephants are no longer an endangered species
考题
共用题干
第三篇Longer Lives for Wild ElephantsMost people think of zoos as safe places for animals,where struggles such as having difficulty finding food and avoiding predators（猛兽）don't exist. Without such problems,animals in zoos should live to a ripe （成熟的）old age.But that may not be true for the largest land animals on Earth.Scientists have known that elephants in zoos often suffer from poor health.Sometimes,they even become unable to have babies.To learn more about how captivity（圈养）affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care,documenting factors such as birth dates,illnes-ses,weight and death.These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born fe-male elephants with the life spans of thousands of wild female elephants in Africa and Asian elephants that work in logging camps（伐木场）, over approximately the same time period.The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years一more than three times as long. Female Asian elephants followed a similar pattern. In zoos,they lived 18.9 years,while those in the logging camps lived 41.7 years.Scientists don't know yet why wild elephants seem to get on so much better than their zoo-raised coun-terparts.Georgia Mason,a biologist at the University of Guelph in Canada who led the study,thinks stress and obesity（肥胖症）may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild,and most are very fat. Social lives of elephants are also much different in zoos than in the wild,where they live in large herds and family groups.The study raises some questions about acquiring more elephants to keep in zoos.While some threatened and endangered species living in zoos reproduce（生殖）successfully and maintain healthy populations,that doesn't appear to be the case with elephants.One of the possible reasons for the zoo-raised elephants'problems is that______________.A:they do not get proper food B:they do too much exerciseC:they live in large herdsD:they do not live in family groups
考题
Since many of the older, bigger-tusked animals have already been destroyed, what did thepoacher do?___________A.They gave up poaching
B.They killed more elephants to get the same quantity of ivory
C.To them, game is over
D.They realized it was illegal to slaughter elephants
考题
African elephants have been slaughtered at alarming rate over the past decade, largely because they are the primary source of the world's ivory． Their population has been dwindled from 1．3 million in 1979 to just 625,000 today, and the rate of killing has been accelerating in recent years because many of the older, bigger tusked animals have already been destroyed． "The poachers now must kill times as many elephants to get the same quantity of ivory," explained Curtis Bohlen, Senior vice president of the World Wildlife Fund．
Though its record on the environment has been spotty so far, the government last week took the lead in a major conservation issue by imposing a ban on ivory imports into the US． The move came just four days after a consortium of conservation groups, including the World Wildlife Fund and Wildlife Conservation International, called for that kind of action, and it made the US the first nation to forbid imports of both raw and finished ivory． The ban, says Bohlen, sends a very clear message to the ivory poachers that the game is over．
In the past African nations have resisted an ivory ban, but increasingly they realized that the decimation of the elephant herds poses a serious threat to their tourist business． Last month Tanzania and several other African countries called for an amendment to the 102 nation Convention on International Trade in Endangered Species that would make the ivory trade illegal worldwide． The amendment is expected to be approved at an October meeting in Geneva and to go into effect next January． But between now and then, conservationists contend, poachers may go on a rampage, killing elephants wholesale, so nations should unilaterally forbid imports right away． The US government brought that argument, and by week's end the twelve nation European Community had followed with its own ban．
What's the author's attitude?A. Subjective
B. Neutral
C. Pessimistic
D. Activ
考题
Why did the African nations welcome an ivory ban?___________A.The rate of killing has been accelerating
B.The US government forbids imports of both raw and finished ivory
C.They realized that the killing of elephants is a serious threat to their tourist business
D.African people advocated an ivory ban
考题
African elephants have been slaughtered at alarming rate over the past decade, largely because they are the primary source of the world's ivory． Their population has been dwindled from 1．3 million in 1979 to just 625,000 today, and the rate of killing has been accelerating in recent years because many of the older, bigger tusked animals have already been destroyed． "The poachers now must kill times as many elephants to get the same quantity of ivory," explained Curtis Bohlen, Senior vice president of the World Wildlife Fund．
Though its record on the environment has been spotty so far, the government last week took the lead in a major conservation issue by imposing a ban on ivory imports into the US． The move came just four days after a consortium of conservation groups, including the World Wildlife Fund and Wildlife Conservation International, called for that kind of action, and it made the US the first nation to forbid imports of both raw and finished ivory． The ban, says Bohlen, sends a very clear message to the ivory poachers that the game is over．
In the past African nations have resisted an ivory ban, but increasingly they realized that the decimation of the elephant herds poses a serious threat to their tourist business． Last month Tanzania and several other African countries called for an amendment to the 102 nation Convention on International Trade in Endangered Species that would make the ivory trade illegal worldwide． The amendment is expected to be approved at an October meeting in Geneva and to go into effect next January． But between now and then, conservationists contend, poachers may go on a rampage, killing elephants wholesale, so nations should unilaterally forbid imports right away． The US government brought that argument, and by week's end the twelve nation European Community had followed with its own ban．
Which of the following is the best title for the passage?A. African Elephants and the Ivory Trade
B. A Bid to Save the Elephant
C. The Poachers
D. Elephants in Danger
考题
共用题干
第二篇Don ' t Count on Dung" Conservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants."say African and American researchers.The error occurs because of a flaw in the way that they estimate animal numbers from the piles of dung（粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees."We really need to know ele- phant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers of- ten estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. " Using the wrong values can lead the census astray（离开正道）,"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Came- roon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in therainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around."This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,"says Plumptre."However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an ele- phant's natural range."The usual technique of monitoring only small,protected areas distorts numbers be-cause elephants move in and out of these regions,"he says."If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evi-- dence such as nests,tracks or burrows（地洞）.Why do researchers estimate elephant numbers in an area by counting dung piles?A:Because elephants are difficult to catch.B:Because it is not possible to count elephants from a plane.C:Because it is not possible to keep track of elephants.D:Because elephants are shy animals.
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第二篇Don't Count on DungConservationists（自然保护主义者）may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers.The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung （粪）the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions,according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees.“We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa.So researchers often estimate elephant numbers by counting dung piles in a given area.They also need to know the rate at which dung decays.Because it's extremely difficult to determine these rates,however,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment.Using the wrong values can lead the censusastray（离开正道）,says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre."However accurate your dung densityestimate might be,the decay rate can severely affect the result.''Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions,he says."If the elephant population increases within the protected area,you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached（入侵偷猎）outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows（地洞）.The word "threatened" in the first sentence of the first paragraph could be best replaced byA:"endangered".B:"frightened".C:"killed".D:"angered".
考题
Why do researchers estimate elephant numbers in an area by counting dung piles?A Because elephants are difficult to catch.
B Because it is not possible to count elephants from a plane.
C Because it is not possible to keep track of elephants.
D Because elephants are shy animals.
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单选题Which of the following is true about ivory?A
After jewelry and carvings, ivory is becoming most popular among the Japanese.B
Most of the ivory products are consumed in Japan.C
Public was angry with the Japanese for their use of ivory.D
International ban in the trade of ivory should be imposed to protect elephants.
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单选题Many elephants were known to have perished of their wounds when there were no nature reserves.A
diedB
treatedC
survivedD
neglected
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单选题Elephants are afraid of bees because ______.A
they are too small to catchB
there are too many of them in the forestC
bees can attach certain parts of the elephant’s bodyD
bees can kill elephants
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单选题Why are elephants endangered?A
They are changing living habits.B
They are driven into thick forests.C
Two species of disease threaten their lives.D
Demand from ivory market leads to their killing.
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单选题What is an effective way of keeping the elephants away from farmland?A
Placing hives full of bees on the farmland that elephants frequent.B
Placing empty bee hives on the farmland.C
Placing either occupied bee hives or empty ones on the farmland.D
Releasing the bees in the face of an approaching elephants.
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问答题There are 1, 200 elephants in a herd. Some have pink and green stripes, some are all pink and some are all blue. One third are pure pink. Is it true that 400 elephants are definitely blue?
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单选题Which one listed below is most dangerous to elephants?A
A disgruntled farmer with a rifle.B
Poachers.C
Mice.D
Bees.
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