prep 1-74 感觉5个选项都无关 马上就考试了 大家帮忙

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

答案给的C  感觉无关

NN们能把思路（逻辑链）说一下吗

我选C

题目中就fertility rates 而言collared females < uncollared females

因而推出some substance in the tranquilizer inhibits fertility

若如C为very often  除了在collar方面  tranquilizer darts 广泛运用于其他方面 即collared 和uncollar 在身体上所接受的 tranquilizer darts 的差异性显著减小 就是说 他们在 tranquilizer darts 上没有明显差异

那么他们之间fertility的不同就和tranquilizer没有关系

所以C的回答足以动摇题干的结论

我选C

题目中就fertility rates 而言collared females < uncollared females

因而推出some substance in the tranquilizer inhibits fertility

若如C为very often  除了在collar方面  tranquilizer darts 广泛运用于其他方面 即collared 和uncollar 在身体上所接受的 tranquilizer darts 的差异性显著减小 就是说 他们在 tranquilizer darts 上没有明显差异

那么他们之间fertility的不同就和tranquilizer没有关系

所以C的回答足以动摇题干的结论