Did you know that if you need an alarm clock to wake up in the morning, you’re probably sleep-deprived （缺失）? ____36_______ . On average, American teens get two hours less than the average 9.2 hours of sleep they need each night to function at their best.

　　There are many reasons why teens don’t get enough sleep. ____37_______ . When your parents were young, they might have read a book or watched television before trying to go to sleep. But today’s teens are likely to be surfing the Internet, texting, emailing, or playing video games right before bed. ____38_______ . And using them right before bed can result in difficulty getting to sleep. According to a survey by the National Sleep Foundation, teens with four or more electronic equipment in their rooms are much more likely than their peers to get an insufficient amount of sleep at night, and are almost twice as likely to fall asleep in school and while doing homework.

　　____39_______ . In the National Sleep Foundation survey, three-quarters of the teens took at least one drink with caffeine every day, and nearly one-third consumed two or more every day. With all the trendy “high-energy” drinks and coffees out there right now, it’s easy to get a caffeine overload and that’s not good for sleep.

　　So what can you do if you’re in lack of sleep? “The good news is that you only have to make up about a third of what you have lost, to function and feel better,” says Dr. Mahowald at a sleep disorders center. ____40_______ . But sleeping until noon on the weekend can cause problems --- you’ll likely be wide-eyed until late those nights. Instead, try keeping a reasonable, regular sleeping and waking schedule.

　　A. One of them is a relatively new development.

　　B．Those extra two hours of sleep on Saturday and Sunday mornings can really help.

　　C．Most teens don’t get enough sleep.

　　D．Many teens also drink too much caffeine to sleep well.

　　E．Electronic devices are more exciting than simply watching television.

　　F．Researchers also have found that biology plays a role in teens’ sleep patterns.

　　G．Many school districts are shifting their start times to later morning for school students.

　　CAEDB

　　Did you know that if you need an alarm clock to wake up in the morning, you’re probably sleep-deprived （缺失）? ____36_______ . On average, American teens get two hours less than the average 9.2 hours of sleep they need each night to function at their best.

　　There are many reasons why teens don’t get enough sleep. ____37_______ . When your parents were young, they might have read a book or watched television before trying to go to sleep. But today’s teens are likely to be surfing the Internet, texting, emailing, or playing video games right before bed. ____38_______ . And using them right before bed can result in difficulty getting to sleep. According to a survey by the National Sleep Foundation, teens with four or more electronic equipment in their rooms are much more likely than their peers to get an insufficient amount of sleep at night, and are almost twice as likely to fall asleep in school and while doing homework.

　　____39_______ . In the National Sleep Foundation survey, three-quarters of the teens took at least one drink with caffeine every day, and nearly one-third consumed two or more every day. With all the trendy “high-energy” drinks and coffees out there right now, it’s easy to get a caffeine overload and that’s not good for sleep.

　　So what can you do if you’re in lack of sleep? “The good news is that you only have to make up about a third of what you have lost, to function and feel better,” says Dr. Mahowald at a sleep disorders center. ____40_______ . But sleeping until noon on the weekend can cause problems --- you’ll likely be wide-eyed until late those nights. Instead, try keeping a reasonable, regular sleeping and waking schedule.

　　A. One of them is a relatively new development.

　　B．Those extra two hours of sleep on Saturday and Sunday mornings can really help.

　　C．Most teens don’t get enough sleep.

　　D．Many teens also drink too much caffeine to sleep well.

　　E．Electronic devices are more exciting than simply watching television.

　　F．Researchers also have found that biology plays a role in teens’ sleep patterns.

　　G．Many school districts are shifting their start times to later morning for school students.

　　CAEDB