填空题
A. fall asleep again
B. become more energetic the following day
C. sleep less than 7 hours
D. confirm those serious consequences
E. suffer sleep problems
F. sleep more than 8 hours
填空题 To get a good night's rest, people may not need to ______.
填空题 Long sleepers are reported to be more likely to ______.
填空题 One of the sleep problems is waking in the middle of the night ,unable to ______.
填空题 One survey showed that people who habitually ______ each night have a higher risk of dying.