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 cannabinoids 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?
Q13 GWD-24-35(CD-10-35) 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? E 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. 这题为什么选E?能选C吗?
其实我觉得这题有一些东西没有交代清楚。比如block这个CAN,是不是症状就是不想进食?还有并没有细细交代APP和REC的联系,只是最后这么粗浅一说,当然看的时候会觉得这个APP就是一种REC,但以GMAT的风格,如果在选项中搞一下,那这题就难很多。比如说选项中多个"appetite is one of those receptors that cannabinoids stimulate in the brain",这样这道题就迷惑很多。不过这就是GMAT的初衷,他们不会给你最完美的题目和最完美的答案,他们只要求你从已知的内容中抽出最合适的东西。