4. The findings indicate that it is all right to sleep for 6.5 hours a night.
A. Right
B. Wrong
C. Not mentioned
答案：A
5. Most of the participants slept for 7 hours a night during the study.
A. Right
B. Wrong
C. Not mentioned
答案：C
6. Sleeping for less than 5 hours each night is better than sleeping for 5 hours
A. Right
B. Wrong
C. Not mentioned
答案：B
7. The study was the first to tell the difference between 7 and 8 hours of sleep a night
A. Right
B. Wrong
C. Not mentioned
答案：A