狒狒逻辑 21题求解，多谢！

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. （原文中没有提到mercury是effective的治疗方法，去掉）

(D) Mercury poisoning can cause deafness in people with venereal disease.  （veneral 导致deafness，去掉）

(E) Beethoven suffered from psychological problems of the same severity as Newton’s. （没有比较两个人的病情。去掉）

我选的A，想法是historian假定了mercury不能在身体被消除，才能进行试验去检查贝多芬的头发有没有mercury

答案是B，有点想不通，唯一我自己能想的解释：历史学家认为mercury治疗veneral，头发中找到mercury就能说明贝多芬得了veneral，如果那时候人们还因为别的原因食用mercury的话，这个推论就不成立，所以这个是假定？那么我觉得正确的应该是people in Beethoven’s time did not ingest mercury to cure other illness,而不是Some people in Beethoven’s time did not ingest mercury.

有没有高手能够解释为什么A不是假设呢？为什么B是正确的？

多谢！

我不是牛人但发表一下意见

A 不一定非要none of 因为只要在头发里找到mercury的trace就行了

B 对B做否定，如果贝多芬时代的每一个人都注射mercury那么在贝多芬的头发里发现mercury的痕迹不能说明如题的结论。

Crystal, Thank you! You helped me a lot to understand B, however still a little bit unclear anout A.

Is that "None of the mercury introduced into the body can be eliminated" means if a person ingest Mecury in different ways, none of it can be eliminated in the body. Actually the history didn't care whether none of it has been eliminated, as long as the only one way "mercury treated veneral "can be traced, it should be fine for history.

Is this right?