Everyone needs to sleep. During the day you work and play; at night you sleep. Your body rests while you are asleep. In the morning you are ready to work, study or play again. If you sleep well at night, you can work or learn better in the day.

Your body grows more while you are asleep. No one can live without sleeping. If a child is tired, he usually needs more sleep. You will be tired or will not be able to listen to your teacher in class or can’t work well if you do not have enough sleep at night. A baby will cry loudly if you wake him or her up when he or she is sleeping. You can work harder at your lessons, after you have had enough rest. Some of the students hope to learn more before exams, so they study till late at night. But they feel very tired in the day and they may forget more.

Boys and girls of eight or nine need ten hours of sleep every night. Your body needs plenty of air when you sleep. If you do not get enough fresh air, you will feel tired when you wake up. While in bed you must not cover your head. Your lung needs to get enough air. If you open your windows at night, you can have plenty of fresh air. Cool air is better than warm air. Boys and girls, get enough sleep if you want to be strong and healthy.

【推荐2】Robots are ①________. They have been into space, into oceans(海洋), and even into volcanoes(火山)! ②It’s not hard to think of the future where robots will do everything humans do.

In the future, robots might see, talk and walk like humans. Some scientists say you will even have robotic(机器人的) friends③几年以后. But if that happens, robots must be able to think and have emotions(感情). Scientists are making robots that can act like animals.

“Today, robots are like actors — they may show emotions, but they don’t feel them,” Professor Steels says, “I want to change ④that.”

“Robots will be more like humans in the future,” Professor Steels says. But most of them will still only do jobs humans can’t do, or don’t want to do. Robots never get bored, tired or scared. So they are ⑤perfect for working in factories and dangerous places.

Everybody needs water. All plants need water. We use water to wash cups, cars, clothes and ourselves.

Where does water come from? It comes from the clouds. The clouds can change into rain. Some of the rain water goes down the ground. Some of the rain water goes down the mountains into streams (小溪). The streams come together to make rivers and lakes.

Water can change itself. When water gets very cold, it will become ice. When water gets very hot, it will become steam (水蒸气).

【推荐1】Robots are ①________. They have been into space, into oceans(海洋), and even into volcanoes(火山)! ②It’s not hard to think of the future where robots will do everything humans do.

In the future, robots might see, talk and walk like humans. Some scientists say you will even have robotic(机器人的) friends③几年以后. But if that happens, robots must be able to think and have emotions(感情). Scientists are making robots that can act like animals.

“Today, robots are like actors — they may show emotions, but they don’t feel them,” Professor Steels says, “I want to change ④that.”

“Robots will be more like humans in the future,” Professor Steels says. But most of them will still only do jobs humans can’t do, or don’t want to do. Robots never get bored, tired or scared. So they are ⑤perfect for working in factories and dangerous places.