费费逻辑宝典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.

 不明白为什么选B，A和C选项又怎么错了？哪位大侠可以帮助解答一下？非常感谢~

A无关，mercury 没必要保持原含量，只要还有就能测到了。

C无关，人们用Mercury治病是一个客观的事实，他是不是有效与这个事实无关。

B正确，因为文章在说的不是Beethoven头发里有没有mercury，而是他是不是得了要用这个东西治的病。如果用mercury是一种时尚，那即使他没得病也可能用mercury，所以取非削弱