新prep cr2-72

uneverknow777

72.(30176-!-item-!-188;#058&005083)



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.

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

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.

答案选A。有哪位朋友帮忙分析下啊~~

sdcar2010

Sample representativeness.

Whenever there is a survey or statistical analysis, one needs to have confidence of the data collected.

The conclusion is that smoking is likely to contribute to depression in teenagers. The premise is that more NEW smokers are depressed than non-smokers. The argument wants to say that smoking CAUSES depression.

But what if it is the other way around? What if depressed people are more likely becoming smokers than non-depressed peopl?

Choice A removes that possibility, thus a correct answer for this strengthener question. Choice A simply vouchers for the representativeness of the data by removing the potential bias when selecting the participants.

Let's look at the following statement: people who spends more time on CD.com can get higher GMAT scores.

To strengthen this statement, you can say:
Two groups of randomly selected students from Beida. At the start, the two groups have comparatively similar GMAT diagnostic scores then one group was sent to the library to study without access to CD.com while the other was sent to the classroom with access to CD.com. The latter groups scores much higher scores in the second GMAT mock test.

To weaken this statement, you can say:
People who spends more time on CD tend to be NN who have higher GMAT diagnostic scores to begin with when compared with the average GMAT participants.

uneverknow777

LS太牛了，分析的很清楚啊，太感谢了，我还有一题不明白，是117题，在另一个贴子，能帮忙看下吗

poyollll

sdcar2010真乃CR届的大神呐，地位堪比ron之于SC，膜拜。。。

海贝520

sdcar2010 发表于 2011-7-28 21:55
Sample representativeness.Whenever there is a survey or statistical analysis, one needs to have conf ...

不好意思求问一下从哪里能看出来The argument wants to say that smoking CAUSES depression
还有strengthen argument的意思可以理解为weaken conclusion吗？

海贝520

sdcar2010 发表于 2011-7-28 21:55
Sample representativeness.Whenever there is a survey or statistical analysis, one needs to have conf ...

不好意思我好像真的还是不太理解，argument哪里透露出了是抑郁导致吸烟的吗？为啥我觉得完全没有呢？我对全文的理解都是：
a study研究不吸烟的少年是否会吸烟，而且吸烟对他们的心理状况的影响。一年后，吸烟者depression的次数是不吸烟者的四倍。因为尼古丁会改变人脑的化学物质，所以可能会影响心情，所以有可能是吸烟影响到了depression。
问：哪个加强了论据
然后我觉得A完全没啥关系= =#已经快看疯了

还是说strengthen argument的问法其实就是weaken conclusion的意思吗？