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 something restful before going to bed. This could be watching TV or listening to music. Doing some exercise【C16】______in the 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】