OG11上面的这道题目,我的脑浆都想出来了还是没搞懂为什么选择D。请各位大虾帮忙!! 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 memtal illness as well as against physical disease. 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 systems. D. Mental illness does not cause people's immune-system activity to decrease. 我第一次选择A,第二次选择B。。。但是无法理解为什么D才是正确答案,望赐教!!Thanks in advance! |