Do you have a good sleep(睡眠) every night? March 21 is World Sleep Day. It's a good time to think about our sleeping habits and get more sleep.
Sleep is important(重要的) because it helps our bodies to recover(恢复) from the stress(压力) of living.
But today, heavy stress and the habit of using smartphones before bedtime make people lose sleep. About 62% of adults in the world feel that they don't sleep well, according to a survey. In America, around 50 million to 60 million peoplesuffer fromsleep problems. Losing just one or two hours of sleep every night can affect(影响) us.
"If you don't get enough sleep at night, you might sleep in school. If you're asleep, you don't learn anything, " says Mary Carskadon, a sleep researcher at Brown Medical School.
How much sleep do you need? That depends on how old you are. The Sleep Foundation says that teenagers(青少年) need 8. 5 to 9 hours a day.
