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【C1】______in bed until the early hours of the morning when you eventually【C2】______asleep. When you wake up, you don't feel【C3】______, but tired and worn out and【C4】______to face a new day.

Dr. Henry Winkle, in a recent newspaper article【C5】______Stress and Sleep,【C6】______that stress and lack of sleep are directly【C7】______. Dr. Winkle says, "the more we worry, the【C8】______we sleep, the more we are unable to deal with【C9】______.” “If we can find a way to get a good night's sleep," he【C10】______,"we can often find the【C11】______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【C12】______a lot. Seven hours is about the average amount,【C13】______strangely enough, sleeping longer often gives you a headache【C14】______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【C15】______and do solnething restful before going to bed. This could be watching TV or listening to music. Doing some exercise【C16】______in tile day should help you to feel physically as well as【C17】______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【C18】______"When you put the light【C19】______," Dr. Winkle says," concentrate on relaxing your muscles. Working slowly up from your feet, and you'll be asleep【C20】______you know it."

【C1】

A．turning

B．rolling

C．twisting

D．rotating