求助：大全-6-16

lenghongmin

A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease.

16.   The researcher’s conclusion depends on which of the following assumptions

(A) High immune-system activity protects against mental illness better than normal immune-system activity does.

(B) Mental illness is similar to physical disease in its effects on body system.

(C) People with high immune-system activity cannot develop mental illness.

(D) Mental illness does not cause people’s immune-system activity to decrease.（D）

(E) Psychological treatment of mental illness is not as effective as is medical treatment.

怎么答案是D呢，我认为根本和原文没有关系呀。而B，恰恰是把原文的结论和experiment加强了联系，虽然不是很标准的assumption但是4个选项中关联度最高的呀？

请NN们帮我解答一下.

lingshihong

题目是说：low levels of immune-system activity 与low on tests of mental health 有关，结论是low levels of immune-system activity 导致了low on tests of mental health 。但我们可以发现，除作者的结论外，还有一种可能：mental health problem导致了low levels of immune-system activity 。显然，作者排除了这种可能。

lenghongmin

恍然大悟。

谢谢。

xiaoyuexing

是不是也就是说有可能是mental自身的问题导致了low on tests of mental health 。而这种情况下low levels of immune-system activity 就是一个无关的原因了？

还是不太明白B。

题干里只讨论了mental一方面的问题。而结论却给出了mental和physical两方面。这不是小范围推大范围吗？如果mental和physical不相似。那有可能结论就是不成立的呀？

菜鸟弱问。思路不清晰。望指点。谢谢。

lindar1009

题目中说明good immune system protects against mental illness结论却给出也给以protectsagainst physical illness.

对D取非，mental illness的存在会导致immune system的降低，那么就无法protcts against physicla illness（根据常识immune system是用来protects against physical illness的）去掉这种可能性，就是对结论的一种假设。