问题
单项选择题
Two groups of people are compared in the third study. They are people().
A.with less than5 hours of sleep a night and with 7 to 9 hours of sleep
B.who slept 4 hours a night and who slept 4 hours for 2 nights
C.with less than 4 hours of sleep a night and with 7 to 9 hours of sleep
D.with less than 5 hours of sleep a night and with 8 hours of sleep
答案
参考答案：C
解析：
[分析]： 细节信息。 题干：在第三项研究中，两组人做了对比，这两组人分别是根据原文“They found that people who got less than four hours of sleep a night…This was compared to people with seven to nine hours of sleep．”，译文为：他们发现一个晚上睡眠少于4小时的人……这和睡眠7到9小时的人做了对比。所以选c。