Enough sleep is important to health. The amount of sleep needed 【小题1】(depend) on the age of the person and the conditions in 【小题2】sleep takes place. The young may need more sleep than the old, but usually eight hours are enough for the health of grown-ups. Some can do with【小题3】than this amount, but 【小题4】may need more. Every person knows his own need. 【小题5】 is then a matter of good judgment to satisfy his need. Sleep 【小题6】 always be enough to make one bring back his 【小题7】(strong) and get ready for a day’s work.

Fresh air is necessary to sound sleep. So it is not without reason for some people to think that it is practicable to sleep in the open air. A bath at bedtime, 【小题8】hot nor cool but of body temperature, may be 【小题9】(help) to sleep. Sleep producing drug(帮助睡眠的药物) should never be taken except when 【小题10】(suggest) by a doctor.