请教prep练习1 72题

aimelviola18

A study followed a group of teenagers who had never smoked and tracked whether they took up smoking and how their mental health changed.  After one year, the incidence of depression among those who had taken up smoking was four times as high as it was among those who had not.  Since nicotine in cigarettes changes brain chemistry, perhaps thereby affecting mood, it is likely that smoking contributes to depression in teenagers.

Which of the following, if true, most strengthens the argument?

A. Participants who were depressed at the start of the study were no more likely to be smokers after one year than those who were not depressed.

B. The study did not distinguish between participants who smoked only occasionally and those who were heavy smokers.吸烟的严重程度不是重点

C. Few, if any, of the participants in the study were friends or relatives of other participants.无关

D. Some participants entered and emerged from a period of depression within the year of the study.

E. The researchers did not track use of alcohol by the teenagers.无关

这题的答案是A 为什么呢？我选的是D，D为何不对？

请NN们来帮忙解答一下，谢谢了！

bucklewes

我觉得，题目的结论是smoking导致depression,而题干中的信息只是给你depression和smoking的动态上的关联，但没有说哪个是因，哪个是结果，即没有给你casual关系。所以，那4倍高的关系，即有可能是因为先depression了而导致开始抽烟，也可能是由于先开始抽烟而出现了depression。 文中的表达，尤其是incidence这个词给我们错觉：depression是smoking造成的，但是实际上原文叙述部分没这个意思。

而选项A,把depression导致抽烟这个可能给排除了。那么就只剩抽烟是因，depression是果这个可能。所以是加强原文结论/

lihanljz

对，此题是典型的因果倒置。两个现象A , B同时出现，原文就妄下结论说是A导致B，或者B导致A；那么要重点反对原因，只需要用相反的关系就可以驳倒它。、

至于D，无关原因。而且有一个小词some,是不定选项。

lorolana

DDDDD解释的好～～