Nappingforawhileatdaytimeisaverysmartandhealthymove．TheMayoClinicsaysnaps（51）___relaxation，bettermoodandalertness，andasharperworking（52）___．A2008Britishstudyfoundthatcomparedtogettingmorenighttimeslee
Napping for a while at daytime is a very smart and healthy move．The Mayo Clinic says naps（51）___ relaxation，better mood and alertness，and a sharper working（52）___．A 2008British study found that compared to getting more nighttime sleep，a mid-day nap was the best way to（53）___ the mid-afternoon sleepiness．
According to the Harvard Health Letter，several studies have shown that people（54）___ new information better when they take a nap shortly after learning it．And，most （55）___，a 2007study of nearly 24，000Greek adults in the Archives of Internal Medicine found that people who napped（56）___ had a 37percent reduced risk of dying from heart disease compared to people who didn't nap．
Of course，napping isn't （57）___ for everyone．If you're suffering from inability to sleep，naps that are too long or taken too late in the day can （58）___ with your ability to fall or stay asleep at night．
But for most，naps can make you feel sharper and happier．Naps provide different benefits（59）___ on how long they are．A 20-minute nap will boost alertness and concentration； a 90-minute snooze（小睡）can （60）___ creativity．
According to prevention．com，you （61）___ a natural dip in body temperature between 1p．m．and 3p．m．A short nap at this time can boost alertness for several hours and，for most people，shouldn't （62）___ being able to fall asleep at night．
Pick a dark，cozy place that's not too warm or too chilly．Prevention．com （63）___ napping on the couch instead of in bed，so you're less （64）___ to snooze for too long．
Surprisingly，the best place to take a nap may be a hammock（吊床）if you have one．A Swiss study（65）___ last year found that people fell asleep faster and had deeper sleep when they napped in a hammock than in a bed．That same rocking motion that puts babies to sleep works wonders for grown-ups，too．
51．A．relieveB．promoteC．operateD．support