题目内容：

阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

Enough sleep is important to health. The amount of sleep 1.(need) depends on the age of the person and the conditions in2.sleep takes place. The young may need more sleep than3.old, but usually eight hours are enough for the health of grown-ups. Some can do with4.than this amount, but others may need more. Every person knows his own need. 5. is then a matter of good judgment to satisfy his need. Sleep should always be enough to make one bring back his6. (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 7. the open air. A bath at bedtime, 8. hot nor cool but of body temperature, may be helpful 9. sleep. Sleep-producing drug should never be taken except when10. (suggest) by a doctor.