一道prep题 1-74

74.   (29534-!-item-!-188;#058&004138)

In a certain wildlife park, park rangers are able to track the movements of many rhinoceroses because those animals wear radio collars.  When, as often happens, a collar slips off, it is put back on.  Putting a collar on a rhinoceros involves immobilizing the animal by shooting it with a tranquilizer dart.  Female rhinoceroses that have been frequently recollared have significantly lower fertility rates than uncollared females.  Probably, therefore, some substance in the tranquilizer inhibits fertility.

In evaluating the argument, it would be most useful to determine which of the following?

A. Whether there are more collared female rhinoceroses than uncollared female rhinoceroses in the park

B. How the tranquilizer that is used for immobilizing rhinoceroses differs, if at all, from tranquilizers used in working with other large mammals

C. How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars

D. Whether male rhinoceroses in the wildlife park lose their collars any more often than the park’s female rhinoceroses do

E. Whether radio collars are the only practical means that park rangers have for tracking the movements of rhinoceroses in the park

答案是C。。。为什么啊？？？米想通，求NN帮忙

再顶~

我觉得C很讲不通啊，不用再考虑除了戴radio callars之外的要注射tranquilizer的情况了啊，因为已经是frequent recollar了，每一次要戴，每一次就需要tranquilizer，已经可以说是药物中的某种物质导致犀牛的不孕不育了……

请NN们多发言~~

这题跟以前我看过的像啊， 选项不一样，  以前我做的时候选一个， 麻醉射击行为本身是不是导致infertility

现在选项变了，  我怎么看，都是5个选项无关。。。。  看来想象力差了。。

同感，我自己做的时候憋了很长时间然后瞎选了一个……

C是说需要考虑除了recollar以外,对犀牛使用麻醉药的频率.

就是说,如果没有recollar的犀牛也常常要用到麻醉药,那么麻醉药导致不育的结论是不成立的.

恩，想通了，解释的很好。谢谢个~~