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光后合成

答案

参考答案：光斑过后的短时间内，林下植物往往还能以较高的光速率进行短时间的光合合成。

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Below is some advice on how to sleep better.
1. Maintain a regular bed and wake time schedule
     Go to bed at the same time every night. Choose a time when you normally feel tired, so that you don't
toss or turn. Try not to break this routine on weekends when it may be tempting to stay up late. If you
want to change your bedtime, help your body adjust by making the change in small daily increments, such
as 15 minutes earlier or later each day. As with your bedtime, try to maintain your regular wake-time even
on weekends.
2. Fight after-dinner drowsiness (睡意)
     If you find yourself getting sleepy way before your bedtime, get off the couch and do something mildly
stimulating to avoid falling asleep, such as washing the dishes, calling a friend, or getting clothes ready for
the next day. If you give in to the drowsiness, you may wake up later in the night and have trouble getting
back to sleep.
3. Keep your room dark and cool
     When it's time to sleep, make sure that your environment is dark. Even dim lights- especially those from
TV or computer screens-can confuse the body clock. Heavy curtains or shades can help block light from
windows, or you can try an eye mask to cover your eyes. The temperature of your bedroom also affects
sleep. A bedroom that is too hot or too cold can interfere with quality sleep.
4. Turn off your television
     Many people use the television to fall asleep or relax at the end of the day. You may even have a
television in your bedroom. However, television actually stimulates the mind, rather than relaxing it. Part
of this is due to content. Late night news and prime time shows frequently have disturbing, violent material.
Even non-violent programming can have commercials that are jarring and loud.
5. Exercise early
     Exercise helps promote restful sleep if it is done several hours before you go to bed. Exercise can help
you fall asleep faster and sleep more soundly-as long as it's done at the right time. Try to finish exercising
at least three hours before bed or work out earlier in the day.
6. Consult your doctor
     Use a sleep diary and talk to your doctor. Note what type of sleep problem is affecting your sleep or if
you are sleepy when you wish to be awake and alert. Try these tips and record your sleep and sleep-related
activities in a sleep diary. If problems continue, discuss the sleep diary with your doctor. There may be an
underlying cause and you will want to be properly diagnosed. Your doctor will help treat the problem or
may refer you to a sleep specialist.
1. To prevent yourself from sleeping too much on weekends, you should _____.
A. go to bed at usual time
B. go to bed 15 minutes earlier than usual
C. go to bed at any time
D. make an adjustment to your bedtime
2. Which of the followings makes it easier for you to have a sound sleep?
A. Watching violent programmes before going to bed.
B. Using heavy curtains or an eye mask to block light.
C. Changing your bedtime only a little every day.
D. Completing your workout just before bedtime.
3. The following ways can help fight after-dinner drowsiness EXCEPT _____.
A. making a telephone call
B. doing some washing
C. having a rest on the sofa
D. taking a walk outside
4. If your sleep problems continue, you'd better _____.
A. move into a new house
B. turn to the doctor for help
C. change your present job
D. discuss it with your family
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单项选择题

实验动物在病毒病的研究上占有重要地位，病毒为什么不能像细菌一样在人工培养基上进行繁殖和鉴定等各项实验（）。

A.病毒只感染动物

B.病毒只感染细胞

C.病毒在人工培养基上感染性降低

D.病毒必须依赖有生命的宿主才能繁殖

E.病毒只对动物敏感
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