求教：费费逻辑21，谢谢。-->ethyl转移

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.

There should be 2 assumptions to support the hypothesis. The 1st assumption of the author is that only venereal disease will be treated by mercury in Beethoven’s time. The 2nd assumption is only some people in Beethoven's time will ingest mercury, if all people ingest mercury, the evidence is not useful. So, some people in Beethoven's time did not ingest mercury. The answer should be B.

A, E have nothing to do with the argument.
C is not necessary, 'Since mercury was commonly ingested in Beethoven’s time to treat venereal disease' is enough.
D is wrong:  according to the author, it is the venereal disease that will cause the deafness, not the mercury poison.

我有点不明白这位牛牛对A的解释

我的思路：
题目：H:可以通过牛顿的头发里的汞来断定牛顿死于汞中毒。虽然没有证据证明贝多芬有过性病，有些人还是假设是性病导致的贝的耳聋，因为在贝多芬时代汞多用于治疗性病 ，所以如果在贝的头发里找到了汞，就可以证明性病导致的贝的耳聋。
问假设
A：进入身体的汞不能被分解。
我就的A应该算一种假设阿，如果汞经过时间分解消除了，学者的证明就不会有意义了。
我市哪里理解出现问题了呢？

另外，对B也不是很理解，nn指教，谢谢。

我开始也觉得A是种假设，但A破坏了原题的前提假设，原题说可以通过牛顿的头发里的汞来断定牛顿死于汞中毒，就暗示了汞是不会随时间分解的。

如果没有B，换句话说，那个时代不管谁，不管有没有性病，只要有兴致都来一口，把汞当“养乐多”（日本一种营养饮料）喝，那不就无法断定贝多芬喝汞是为了治性病，就推不到最后的结论。

谢谢likui的解释,给我了一点启发.

现在能看懂一些B的解释了,但感觉B并不是很严谨.

如果B改为只有veneral的患者用mercury, 而其他的人不会用,是不是更合理些?

b只提到some people不用mercury,太模糊了.

谢谢