Here is a statistic(数据) that will surprise you.More young people are killed each year by slee...

Here is a statistic(数据) that will surprise you.More young people are killed each year by slee...
Here is a statistic(数据) that will surprise you.More young people are killed each year by sleepy drivers than by drunk drivers.This proves one thing.Getting enough sleep can be a big problem.How are we dealing with the problem?Sleep clinics are popping up all over the United States.They are always working to find out more about sleep.Driving when tired can be very dangerous.During the daytime,over half of drivers report feeling sleepy at some point.At night,over 80 percent of drivers sometimes get drowsy.And here is the most frightening of all.Almost one-quarter of all drivers have fallen asleep at the wheel.
What is going on here?One thing is that people are not getting enough sleep.One person out of three gets by on less than six hours a night._______________________.Others fall asleep easily,but then wake up time after time.Few people get enough of the deep sleep they need to feel really rested.
Here are some facts to remember.Believe it or not,people need seven to nine hours of nighttime sleep to remain healthy.During that sleep,a person's immune system is built up.This helps fight off diseases and infections.And taking a nap in the daytime does not really help.It will make a person feel “““refresh”””ed.But it cannot make up for the lack of nighttime sleep.
What if you are a person with real sleeping problems?What if you have tried all the home remedies like hot milk?You might consider going to a sleep clinic.Many such clinics look for volunteers.They will study your sleep problems,and you will not have to pay anything.
（1）what is the best title of the passage（no more than 5 words）
（2）complete the following statement with proper words（no more than 4 words） if you have sleep clinic where yov could get help ————
（3）fill inthe blank （para.3） with proper wordr or phrases （no more than 10 words）
（4）why do people need seven to nine hours of nighttime sleep（no more than 10 words）
（5）what does the word “it”（linef,para.4）probably refer to （no more than 6 words）