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  3. 共用题干 第二篇Don't Count on Dung（粪便）Conservationists（自然保护主义者）may be miscalculati...

共用题干 第二篇Don't Count on Dung（粪便）Conservationists（自然保护主义者）may be miscalculati...

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问题 共用题干
第二篇

Don't Count on Dung（粪便）

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 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 census astray（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 percent 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 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 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 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 evidence such as nests,tracks or burrows（地洞）.
选项 Piles of dung can't be relied upon when it comes to estimating elephant numbers because______.
A:they are different in size
B:they scatter an over the region
C:they are different in decay rate
D:they are different in quality
答案C
解析threatened：有灭绝危险的。threatened animals：有灭绝危险的动物。endangered：有灭绝危险的，有生命危险的，例如：an endangered species：一个有灭绝危险的物种。 frightened：受惊的。killed：杀死了的。angered：激怒了的。因此A是正确答案。
该题意思是“为什么研究人员通过数粪堆佑计一个地区的大象数量”。第四段的第一、二句告诉我们：从飞机上数中非广阔的雨林中的大象数量是不可能的，研究人员通过数粪堆佑计一个特定区域的大象数量。因此B是正确答案。
该题问的是“不可依据粪堆数估计大象数量的原因是什么”。文章第五段第一句话指出：由于气候和环境的不同，这个腐烂比率会随地区的变化而变化。可见C是正确的答案。A：它们的大小是不一样的。B：它们散布在整个地区。D：它们的质量是不一样的。
该题意思是“根据Plumptre的观点，选择粪堆普查的地区应符合什么样的条件”。倒数第二段提到了Plumptre的观点，即普查的地区应该大到不能使象自由出入，也就是说，必须足够大。A：足够小。B：得到了很好的保护。C：得到了密切的监控。因此D是正确答案。
第六段的第一个词He指谁？一般情况下，代词回指的词必须离得很近。因此必定是上段结尾处的Plumptre。
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