GWD24-35

jessiecg

The milk of many mammals contains cannabinoids, substances that are known to stimulate certain receptors in the brain. To investigate the function of cannabinoids, researchers injected newborn mice with a chemical that is known to block cannabinoides from reaching their receptors in the brain. The injected mice showed far less interest in feeding than normal newborn mice do. Therefore, cannabinoids probably function to stimulate the appetite.



Which of the following is an assumption on which the argument depends?

A.Newborn mice do not normally ingest any substance other than their
mothers’ milk.

B.Cannabinoids are the only substances in mammals’ milk that stimulate the appetite.

C.The mothers of newborn mice do not normally make any effort to encourage their babies to feed.

D.The milk of mammals would be less nutritious if it did not contain cannabinoids.

E.The chemical that blocks cannabinoids from stimulating their brain receptors does not independently inhibit the appetite.

答案是E，我选的C,不懂为什么。觉得C排除了一个让结论不能达到的原因，也是取非削弱结论啊。
  请大牛们指点~

jessiecg

求救啊~

judydongxueni

c无关啊，题干里根本没有提到mice妈的问题啊

jessiecg

又是版主好人帮忙啊。哈哈，谢谢
可是无关词的方法到底怎么用啊？
我发现我不太会用啊。。。。
总是区分不出来

hjxsparrow

题干：
milk中有c，c可以刺激脑中的感受器r，对老鼠的实验中，研究人员用化学物质阻断了c接触r，结果被实验的老鼠的食欲相比正常老鼠大幅下降
得出结论c用来刺激食欲

正确答案E选项，取非后 该化学物质本来就可以抑制食欲，则上述推理不成立

C是无关选项，直接与结论无关。 文中推理过程在上面，而妈妈是否刺激baby进食与上述的推理过程完全没有任何关系。
就算取非，妈妈刺激baby进食，被化学物质阻断C接触R的老鼠还是食欲下降，还是可以得出结论C刺激食欲，并没有削弱结论

jessiecg

Thanks!