Enough sleep is important to health. The amount of sleep __1________(need) depends on the age of the person and the conditions in _2.________ sleep takes place. The young may need more sleep than __3.________ old, but usually eight hours are enough for the health of grown-ups. Some can do with ___4_______ 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 his __6.__________ (strong) and get ready for a day’s work.

Fresh air is necessary to sound sleep. So it is not __7.___________ reason for some people to think that it is practicable to sleep in 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 when _10.________ (suggest) by a doctor.