问feifei 第4题

Hendy

4. The gray squirrel, introduced into local woodlands ten years ago, threatens the indigenous population of an endangered owl species, because the squirrels’ habitual stripping of tree bark destroys the trees in which the owls nest. Some local officials have advocated setting out poison for the gray squirrels. The officials argue that this measure, while eliminating the squirrels, would pose no threat to the owl population, since the poison would be placed in containers accessible only to squirrels and other rodents.

Which one of the following, if true, most calls into question the officials’ argument?

A.       One of the species whose members are likely to eat the poison is the red squirrel, a species on which owls do not prey.

B.        The owls whose nesting sites are currently being destroyed by the gray squirrels feed primarily on rodents.

C.        No indigenous population of any other bind species apart from the endangered owls is threatened by the gray squirrels.

D.       The owls that tare threatened build their nests in the tops of trees, but the gray squirrels strip away back from the trunks.

E.        The officials’ plan entails adding the poison to food sources that are usually eaten by rodents but not by other animals.
E答案怎么理解？

三塘木

这道题是B吧。用helr的方法来理解的话：
结论：eliminating the squirrels; pose no threat to the owl population
前提：the poison would be placed in containers accessible only to squirrels and other rodents.

这里是明显的因果关系推理，针对因果关系，CQ有要么证明因和果没有相关性，要么证明有干扰因素导致果推不出来（前提的因+选项就推不出来果了）。所以最方便的就是看选项哪个会对结论产生最致命的打击。
A 我们对red squirrels不关心，它也不是owls的prey，对结论的毒药只会杀死灰松鼠和啮齿动物不会杀死猫头鹰没有影响。
B 这个很绝对的导致了结论推不出来，这个毒药会杀死啮齿动物，而猫头鹰的主要食物来源是啮齿动物。
C 不相关
D 不相关
E 看这个不要受B的影响，在题目里完全没有提到啮齿动物是猫头鹰的食物来源，只是提到了啮齿动物也会吃这种毒药，那么这个就只是原题条件的陈述，对于原来的结论没有任何影响。就算灰松鼠吃的少了，但是只要灰松鼠有吃到这种毒药死了同时毒药也不影响猫头鹰，那这个方案在原先的逻辑下就是有效的

小MMM

场景：松鼠威胁了猫头鹰的生存，因为松鼠的领地占据了猫头鹰的领地。官员要毒松鼠，毒药不会对猫头鹰造成影响。只有松鼠和其他rodents能access毒药。
分析：官员的举措是毒松鼠，这个举措有什么问题？【方案型】
预想：“方案真的能实现目标吗？这个方案能做到吗？方案有没有什么副作用？目标本身靠谱吗？”即可以从这些方面思考：
•        毒松鼠了，猫头鹰就不会endangered了吗？
•        松鼠真的会被毒到吗？
•        用毒药这种方法有没有什么副作用？【本题】毒了其他的rodents，这些rodents正好是猫头鹰的食物。注意B选项的句子主干是“The owls feed primarily on rodents”。