根据短文内容，完成下列各题。
Most teens
need more than 9 hours of sleep each night. But about 1 in 4 teens has trouble
in sleeping. Lack of sleep can affect everything from our feelings to how well
we focus on tasks like studying. It can also influence sports performance,
increase our chances of getting sick, and may lead to weight gain in some
people.
How can we
get the sleep we need? Here are some ideas:
Be active
during the day. Get at least 60 minutes of exercise a day. Physical activity
can decrease stress and help people feel more relaxed. Just don't work too
close to bedtime because exercise can wake you up before it slows you down.
Say
goodnight to electronics. Experts suggest using the bedroom for sleep only. At
least shut everything down an hour or more before lights out.
Keep a
sleep routine. Going to bed at the same time every night helps the body expect
sleep. Creating a bedtime routine can improve this relaxation effect. Reading,
listening to music, spending time with a pet, writing a diary or doing anything
else can relax you.
Expect a
good night's sleep. Instead of worrying that you won't sleep, remind yourself
that you can. Say "Tonight, I will sleep well." several times during
the day. It can also help to practise breathing exercises or gentle exercises
before bed.
Everyone
has a sleepless night once in a while. But if you regularly have trouble in
sleeping and you think it's affecting your mood or performance, talk to your
doctor.
