Studies have shown that a good night's sleep helps us stay healthy.People who study it say sleep is maybe the best for our memory（記憶） and learning.
   "Getting a good night's sleep is important for learning and memory because it keeps the training and learning exercises into our memory forever while we are sleeping 7-8 hours in bed，" Twery，an expert（專家） on the science of sleep said.
   But what about sleeping during the middle of the day？Studies have shown that napping can help young children learn better.In fact， napping can help the older and may also help them fight off age—related（年齡相關）memory losing.
   They studied 3，000 people and found that those who took an hour-long nap did much better on mental（智力的）tests.The hour-long nappers also did better than those who napped for shorter and longer time.But these findings are for those over 65，and for young，healthy adults，an hour-long nap may be too long.
   "We should try to nap for about 30 minutes or less.Thirty minutes is enough to help us relax and feel awake.If we nap longer，we will get into（陷入）the deep sleep，which can be hard to get out of，" Twery said.For a time，you are unable to think clearly.

（1）What can we learn from Paragraph 1？

D

D

A．A good night's sleep is usually 7-8 hours.
B．A good night's sleep makes people become smarter.
C．A good night's sleep makes people wake up early in the morning.
D．A good night's sleep helps with people's learning and memory.
（2）What does the underlined word "napping" in Paragraph 3 mean？

C

C

A．a deep sleep at night
B．a long sleep at night
C．a short sleep during the day
D．a good sleep during the day
（3）What does the result of the study show？

D

D

A．The hour-long nappers are much smarter.
B．Young adults need more napping time.
C．The deeper you sleep，the longer you'll sleep.
D．The time of napping should be different for different ages.
（4）What is the passage mainly about？

B

B

A．How is napping good for people's health？
B．Napping may improve learning and memory.
C．The importance of having a good night's sleep.
D．How long should people take a nap during the day？
（5）Which part of a newspaper can we find the passage from？

C

C

A．Nature.
B．Sport.
C．Health.
D．Culture.