题目内容：

Do teenagers know how to sleep? If you’re the parent of teens, you might be laughing to yourself. That’s all they know how to do. In truth, teens might not know enough about how to sleep, when to sleep and why.1. .

Just as we focus on our diets and exercise for health, we need to consider sleep necessary to our mental, physical and psychological health. “Good” sleep is sleep that is long enough to allow your brain to remove the side effects of daytime brain activity. Consistent bed times and wakeup times are the key to keeping our sleep cycles.2..

Teens are social creatures, and the most attractive social “gathering” place these days is on their digital devices.3.. Ideally, we should avoid blue light for at least half an hour before bed. But social media and homework that requires screen time mean too many kids are powering up their devices when their bodies should be powering down for the night.

4.. Equally contributing to sleep issues are eating too late, taking naps, and failing to get enough exercise. In other words, these people never learned how to sleep.

Over time, poor sleep leads to a decline in mood.5.. Significantly, when I speak to my adult patients who are struggling with sleep issues, nearly all of them say their sleep problems started in high school.

Therefore, I recommend sleep education. Otherwise, we won’t necessarily solve the health, safety and economic issues of sleepy teens.

A. When they are disturbed, our sleep is affected

B. Going to bed too late is only one part of sleep problems

C. Being exposed to blue light from our screens delays sleep

D. Current school schedules allow for about seven hours of sleep a night

E. It also contributes to a lot of medical issues, from being fat to heart disease

F. Later school start time really contributes to more sleep and improved health

G. As far as I’m concerned, one important element is missing: sleep education