单项选择题

If you are worried about things and are under a lot of stress at work or school, then you are probably not sleeping well. Worry can keep you awake, tossing and 1in bed until the early hours of the morning when you eventually 2 asleep. When you wake up, you don’ t feel 3 , but tired and worn out and 4 to face a new day. Dr. Henry Winkle, in a recent newspaper article 5 Stress and Sleep, 6 that stress and lack of sleep are directly 7 . Dr. Winkle says, "the more we worry, the 8 we sleep, the more we are unable to deal with 9 If we can find a way to get a good night’ s sleep," he 10,"we can often find the 11 to deal with what’ s worrying us. " So, what is a good night’ s sleep Research shows that the amount of sleep which people need in order to keep healthy 12 a lot. Seven hours is about the average amount, 13 strangely enough, sleeping longer often gives you a headache 14 of making you feel more refreshed. Dr. Winkle believes that preparing for sleeping is important. People who work late should try to give themselves a short 15 and do something restful before going to bed. This could be watching TV or listening to music. Doing some exercise 16 in the day should help you to feel physically as well as 17 tired. A bedtime drink can also help, but coffee or tea should be avoided as they contain caffeine(咖啡因) and will keep you. 18. "When you put the light 19," Dr.Winkle says, "concentrate on relaxing your muscles. Working slowly up from your feet, and you’ll be asleep 20 you know it. "

A.turning
B.rolling
C.twisting
D.rotating