Enough sleep is important to health. The amount of sleep needed 31 on the age of the person and the conditions in 32 sleep takes place. The young may need more sleep than 33 old, but usually eight hours are enough for the health of grown-ups. Some can do with 34 than this amount, but others may need more. Every person knows his own need. 35 is then a matter of good judgment to satisfy his need. Sleep 36 always be enough to make one bring back his 37 (strong) and get ready for a day’s work.
Fresh air is necessary to sound sleep. So it is not 38 reason for some people to think that it is practicable to sleep in the open air. A bath at bedtime, 39 hot nor cool but of body temperature, may be helpful to sleep. Sleep-producing drug(帮助睡眠的药物) should never be taken except when 40 (suggest) by a doctor.31 depends 32 which 33 the 34 less 35 It
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(答案→)31 depends 32 which 33 the 34 less 35 It
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