March 21 is World Sleep Day. It reminds us to think about our sleeping habits and try to sleep better. How much do you know about sleep? Sally, Tom, Jack, John, Lucy and Ben are asking questions about sleep. Which of the following can best answer their questions?
— Nobody has the perfect answer to this question. Scientists did tests on rats. If rats don't sleep for over four weeks, their bodies become colder and smaller. And later, they die.
— Different people need different amounts of sleep. Many surveys show that adults need to sleep about 7 to 8 hours a day. But younger people need more sleep. Doctors advise 10 hours for primary school students, nine for junior high students and eight for senior high school.
— Most of us dream every night. Sometimes you can remember your dreams. But if your sleep is deep enough, you may not remember your dreams.
— Many people feel like they don't get enough sleep on weekdays, so they like to sleep for long hours on weekends. But does this make up for the loss? Doctors don't think so. You may feel better for a short time, but your body is already hurt. What's worse, this changes your body clock. The next day, you may find it hard to fall asleep.
— There are several ways you can do. For example, you can drink a cup of milk or listen to soft music before you go to sleep. Comfortable bedding also helps.
