Your body produces a chemical called melatonin that helps you sleep. Light affects the amount of melatonin your body makes. It produces more in the evening and less in the daytime. So at night turn off your TV and computer. Also, don’t read from a backlit device like an iPad. Some scientists think that the light from those devices stops your body from making melatonin. So turn those screens off at least an hour before bedtime.
turn off：關閉（shut off、switch off、shut down）
Maybe you can’t sleep or you wake up in the middle of the night. Don’t just lie in bed. Get up and do something relaxing elsewhere. Then go back to bed when you feel drowsy. If you worry a lot, make a list of things you need to do the next day. Do that an hour before bed. That way you get your worrying out of the way before you go to bed.
After a good night’s sleep, you’ll be able to face a new day.
get … out of the way（擺脫/拋開…）
studies show …：研究指出