题目内容：
根据以下材料，回答题Enoughsleepisimportanttohealth.Theamountofsleep21dependsontheageoftheper-sonandtheconditionsinwhichsleep22.Theyoungmayneedmoresleepthantheold,butgenerallyeight
hoursareenoughforthehealthofgrown-ups.Somecan23withlessthanthisamountbut24mayneedmore.Everypersonknowshisownneed.Itisthenamatterofhowto25it.Sleepshouldalwaysbeenoughtomakeonerelaxed(松弛)andreadyfor26work.
Freshairis27tosoundsleep.Itisnotwithoutreasonforsomepeopleto28thatitispracticaltosleepintheopenair.29apersoncankeephimselfwarm,out-of-doorsleepingprobablygivesthebody30completerelaxation.
Abilitytosleepislargelyahabit.Theconditionsreferredtoonlyleadtosleep.Out-of-door31,agoodhabitofregulardrinkingandtheavoidanceoflateeatingand32areallhelpfultosoundsleep.Suchfactorsarelargelywithinthecontrolofanyperson.Abathat33,neitherhot
norcoldbutof34temperature,maybehelpfultosleep.Sleepingpillsshouldneverbetakenexceptwhensuggestedby35
A．Wished
B．Expected
C．Needed
D．wanted
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答案解析：