真的看不懂

Researchers took a group of teenagers who had never smoked
and for one year tracked whether they took up smoking and how their mental
health changed. Those who began smoking within a month of the study’s start
were four times as likely to be depressed at the study’s end than those who did
not begin smoking. 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 strengthen the
argument?

Ø       Participants who were depressed at
the study’s start were no more likely to be smokers at the study’s end than
those who were not depressed.

Ø       Participants who began smoking within
a month of the study’s start were no more likely than those who began midway
through to have quit smoking by the study’s end.

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

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

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

怎么也看不懂， 谁帮帮我啊

就是通过实验来研究吸烟对青少年行为健康的影响吧。答案是C么？

题干：在学期开始就吸烟的学生在学期末的时候比不吸烟的学生更有可能得抑郁。

Participants who were depressed at the study’s start were no
more likely to be smokers at the study’s end than those who were not depressed.

在学期开始有抑郁学生在学期末的时候并没有比那些不抑郁的学生更可能成为吸烟者

Ø       Participants who began
smoking within a month of the study’s start were no more likely than those who
began midway through to have quit smoking by the study’s end.

在学期开始一周就开始吸烟的学生并没有比在中途开始吸烟的学生更可能直到学期末戒烟。