People spend about 1/3 of their lives doing one thing: sleeping. Every year, there is a day for people around the world to celebrate the importance of good and healthy sleep — World Sleep Day. This year, it falls on March 16. The theme (主题) is “Breathe Easily, Sleep Well.”

Sleep is like food for the brain (大脑).  sleep helps the body and brain grow and develop. People of different  need different hours of sleep. According to the Nation Sleep Foundation in the US, adults need seven to nine hours of sleep every night. For students aged 10 to 17, they need about eight to nine hours per night.

However, many students don't  enough sleep because of early school starting time and too much homework. The China Youth and Children Research Center reported that about 80% of middle school students don't get enough sleep.

Lack (缺乏) of sleep affects (影响) a person's life greatly. Students  enough sleep may get  grades. Because they cannot pay attention in class or do well in sports.

To solve (解决) this problem, scientists advise that students should get less school work and  time to sleep. There are some other ways to help people get enough sleep, such as taking a 20-minute nap (午睡) during the day. Good sleep habits are also . For example, try to go to sleep and wake up at the same time every day, even on weekends and during holidays.