Q37:

Rabbits were introduced to Numa Island in the nineteenth century.  Overgrazing by the enormous population of rabbits now menaces the island’s agriculture.  The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere.  There is, however, a chance that the virus will infect the bilby, an endangered native marsupial.  The government’s plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

Which of the following, if true, most seriously weakens the argument?

1. There is less chance that the virus will infect domestic animals on Numa than that it will infect bilbies.

2. There are no species of animals on the island that prey on the rabbits.

3. Overgrazing by rabbits endangers many of the plants on which bilbies feed.

4. The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

5. There is no alternative means of reducing the rabbit population that would involve no threat to the bilby.

选C, 排除法

但是感觉C也有问题,兔子危害了许多BILBY的食物,但还是有留下的,那么还是会危及Bilby

谁能帮我绕出来啊

The government’s plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife

推理是：使用病毒会威胁到billy，所以计划使农业受益，但威胁野生动物

即“病毒感染”－－》“威胁野生动物”

问削弱

病毒-->减少兔子数量－－》增加野生动物食物－－》反而保护了野生动物

即病毒有一定的几率感染野生动物，但是兔子对野生动物的影响更严重，直接威胁到了食物。因此，消灭兔子能更大程度上的保护野生动物－－－》政府的计划不仅使农业受益，同时也使得野生动物得到相对较好得保护。