feifei2-22

quellekind

Historian: We can learn about the medical history of individuals through chemical analysis of their hair. It is likely, for example, that Isaac Newton’s psychological problems were due to mercury poisoning; traces of mercury were found in his hair. Analysis is now being done on a lock of Beethoven’s hair. Although no convincing argument has shown that Beethoven ever had a venereal disease, some people hypothesize that venereal disease caused his deafness. Since mercury was commonly ingested in Beethoven’s time to treat venereal disease, if researchers find a trace of mercury in his hair, we can conclude that this hypothesis is correct.

 Which one of the following is an assumption on which the historian’s argument depends?

(A) None of the mercury introduced into the body can be eliminated.

(B) Some people in Beethoven’s time did not ingest mercury.

(C) Mercury is an effective treatment for venereal disease.

(D) Mercury poisoning can cause deafness in people with venereal disease.

(E) Beethoven suffered from psychological problems of the same severity as Newton’s.

为什么选B啊？

nieyuhang

题目的结论是，如果Beethoven的头发里发现汞的话，说明venereal是导致他耳聋的原因。给出的依据是，mercury在贝多芬时代普遍用来治疗venereal。其实作者得出结论有三个假设。
第一，venereal是可能导致耳聋的。
第二，mercury在贝多芬时代只会被治疗venereal。（这个题目里用了commonly，勉强算已经符合）
第三，不患venereal的人不会服用mercury。
答案中b就是第三个假设，如果所有人都服用mercury，根本无法得知是否得病。答案a中的elimilated，答案c中的effective treament，答案d中的mercury poisoning 和答案e都属于无关选项。

quellekind

非常感谢哈!!!

mingzhu

我选的是A，因为进入身体的汞不被排出才能被后来的人检测出来，这应该是一个前提吧？不会是无关的；

B所说的Some People和原文的范围不对，原文说的是汞常被用于治疗性病，有些人不摄入汞并不是说没有病的人不摄入汞，你觉得呢？

nieyuhang

楼上的分析本身不是很错，可是gmat逻辑讲究的是直接推理，不能根据自己的“常识”判断，也不能递进推理。
关于a，说的是进入身体的汞不会被消除。题目中并没有说eliminated了就从头发中检验不出来了，它难道不能被消除前部分转化成其它物质然后再从头发里被检验出来吗？当然这个是我随便说的，只是存在这种情况的可能。如果题目中给出的条件建立了eliminated和traces of mercury之间的逻辑桥梁，那么可以考虑这个因素。
关于b，gmat逻辑讲究论据的有效性，而不是充分性。some people 没有服用，反过来就all people 都服用，是对题目的削弱，这就够了，不需要讨论some people到底是哪一部分人，是没得性病的人，还是得了其它病的人。