共用题干 Owls and Larks
1 In this article,we look at the importance of sleep for learning. Most healthy adults need eight or more hours of sleep. But why do we need sleep in the first place?We need sleep for the brain to get a chance to rebuild memories stored during the day and associate these with previously learned things. If this process is interrupted by,say,the sound of an alarm clock,it may not be as effective. So if your sleep is cut short by the alarm clock,how dama- ging is it?The truth is that it"s difficult to predict,as so much depends on how much sleep your body actually needs on that particular occasion.
2 The popular belief that people are naturally either larks(early risers)or owls is false. The reason why people tend to be one or the other has more to do with lifestyle,age,and personality. Many people who appear to be early birds may have just become so through hab- it,for example,parents with very young children. Teenagers can have difficulty falling asleep until late at night and then they naturally have problems getting up the following morning.
3 The main reason why owls are owls is that they tend to spend their time over a book, movie,or computer game till the early hours of the morning. They enjoy the quiet of the night when they can pursue their passion. On the other hand,larks can make better use of early morning hours where they can study in quiet at the time when their brains are most refreshed. So which is better for learning一an owl"s or a lark"s lifestyle?The simple truth is that it is more complex than simply being one or the other. Leading a well-balanced life in terms of work and play and sleeping enough to bring maximum refreshment is probably the secret.
4 As for naps, experts on insomnia（失眠）argue against taking naps, as these may keep people up at night. If your nap lasts only five minutes to half an hour and does not affect your ability to fall asleep in the night,it will probably help you be more alert in evening hours.
However,if you are having problems getting to sleep at night,it"s not only naps that you should avoid. Try not to drink a lot of alcohol, take nicotine（尼古丁) , do mentally intense activities like preparing for exams or doing exercise in the evening. Some people swear that drinking coffee never stops them from sleeping like a log,whereas others will never go near the stuff for fear of being awake all night. However,the best advice for most is to avoid it in the evening,and if you drink coffee before a nap,remember you are likely to awaken as soon as the caffeine starts kicking in. Sleep helps brain to______.