我相信总有人会做对,FeiFei-21，你选什么？

21. 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.

这个毛病传来传去的，晕，希望大家告诉解题思路，谢谢！

结论是we can conclude that this hypothesis is correct

hypothesis是venereal disease caused  deafness

已知是deafness和mercury  treats venereal disease

所以要有桥梁把mercury扯进去，推出venereal disease caused  deafness

我觉得选D答案是什么

原文推理：因为那时人们用M去治性病，所以如果发现头发中有M，就知某某有性病（性病导致耳聋）。隐含的假设是没有别的原因导致头发中有M。B排除其他原因导致头发有M，故为假设。将B取非： All （注意不是SOME） people in Beethoven’s time  ingested  mercury。则说明头发中的M并非治性病导致，而是吃M导致，原文结论不能成立。

原文是想推Beethoven had a venereal disease

我在选B的时候一直在想，为什么要用some呢，而不是用all。如果用all的话，这个assumption就非常完美了。

现在看来，还是对assumption的理解有分歧。如果说assumption是必要条件的话，这个some也很奇怪呀。要是some里面不包括贝多芬怎么办？还是说assumption只能通过取非来确定正确与否？

是呀。这个推导是这样的：性病导致耳聋，又因为用M去治性病。所以如果发现头发中有M，就能推导出耳聋。

这中间的assumption是，平常没事不会吃M（排除导致M出现的它因）。