Let me tell you a story. Long long ago there were ________ mountains in northern China. One was Taihang Mountain; the other was Wangwu Mountain. In the north of the mountains, there was a big family.

The grandpa in the family was called Yugong. Because the mountains were ________ their house, he and his family had to walk long to get to the town on the southern side.

One day Yugong thought, “It’s so ________ to go out like this! I’m an old man now, but I have children. For them and their children and their ________ children, the road to the outside world cannot be blocked that way by the mountains. We should try to let them have a chance to ________ to know the world! “

Hearing what Yugong said, people pulled ________ together and made up their minds to remove the two mountains. However, the mountains were so _________ that people can’t see their tops. The whole family couldn’t dig very much each day ________ they didn’t give up and kept on digging day after day.

Their perseverance (坚持) deeply touched their ________. Some children even came over to help.

An old man named Zhisou in a neighboring village heard about this and came by just to talk with Yugong about it. “It was so unwise of you to make such a decision. You and your family don’t have enough energy. How could you ________ remove the huge mountains? Let them stop now. Don’t waste any more time!” he said.

Yugong ________ and said slowly, “You are wrong. When my sons are getting old, I still have grandsons here. My grandsons will have their children and their children’s children. The family is ________ . While the height of the mountains cannot be increased any more. We must make our dream ________ one day.”

The Jade Emperor (玉皇大帝) was touched by Yugong’s perseverance. He ordered two deities (神仙) to ________ the two mountains away on their backs, putting them in a place ________ Yugong’s house.

①Eating good food and getting proper exercise are important to stay healthy. Getting enough sleep is important, too. Experts say that teenagers between the ages of 15 and 20 need 8 to 10 hours of sleep each night.

②Your body needs to take a rest from all the activities it has done during the day. Your brain needs a rest, too. You are likely to get sick easier without enough sleep.

③You have a “24-hour clock” inside your body that tells you when to be awake and when to go to sleep. ▲ Blue light that comes from the Sun tells your brain to keep you awake during the day. When there is no blue light at night, the brain tells the body that it’s time for sleep.

④There are many things that stop the brain from telling your body when it’s time to sleep. One of these is blue light at night. Today, people spend a lot of time watching television or looking at screens on computers or smart phones. These devices (装置) give off blue light. If you look at them at night, the blue light can trick your body into thinking it’s daytime. Then it is more difficult to go to sleep.

⑤What should you do to get good sleep? Experts say that you shouldn’t look at screens that give off blue light for at least one hour before going to sleep.

⑥ Do not watch TV or use anything with a computer screen in bed. If you need to do something to fall asleep, it is better to read a book. Also, keep your bedroom as dark as you can. This will help you sleep well.