56. As we know, we put food on a plate and water in a glass on earth. Gravity(引力) holds the food down and keeps the water in the glass. But in space, there is almost no gravity. So food can float away, and astronauts must eat and drink carefully.

57. in space, sleeping is very different. Some astronauts like to float in the air, but some astronauts like to be in a sleeping bag. They tie the bag to a wall so that they can’t float at night.

58. Exercise is very important in space. On earth, your legs carry your body, but in space, astronauts float, so they do not use their legs. This is bad for their legs, or they exercise for   thirty minutes every day. They often use an exercise bike for this.

59 Many people can use computers, but few of them know how to look after them. Remember the following when you use computers: Keep your computer in a cool, dry room; do not put water or food near your computer; keep you screen clean and not too bright.

60. Some things can carry messages. For example, a sing at the bus stop helps you to know which bus to take. Sings on the door tell you where to go in or out. Have you ever noticed that there are a lot of signs around you and they you receive messages form them all the time?

Can you imagine astronauts' everyday life in space? They also need to eat,  sleep, exercise and relax. They do the same things as us, but they do them differently.
On Earth, we put food on a plate. Gravity holds the food down and keeps it on a place. But there is almost no gravity in space, so food can float （漂浮）away, and astronauts must eat carefully.
Sleeping is very different in space. Some astronauts like to float in the air, but most like to be in a sleeping bag. They tie the bag to a wall so that they won't float away at night.
Exercise is very important in space. On Earth,  your legs carry your body,  but in space, astronauts float, so they do not use their legs often. This is very bad for their legs, so they must exercise for thirty minutes every day.
After a day's work, astronauts relax. They may listen to music, read, watch films, play games, or talk to their friends and families on the radio. Sometimes they just enjoy floating in the air.
【小题1】What does the underlined word "gravity" mean in Chinese?

Can you imagine astronauts' everyday life in space? They also need to eat,  sleep, exercise and relax. They do the same things as us, but they do them differently.

On Earth, we put food on a plate. Gravity holds the food down and keeps it on a place. But there is almost no gravity in space, so food can float （漂浮）away, and astronauts must eat carefully.

Sleeping is very different in space. Some astronauts like to float in the air, but most like to be in a sleeping bag. They tie the bag to a wall so that they won't float away at night.

Exercise is very important in space. On Earth,  your legs carry your body,  but in space, astronauts float, so they do not use their legs often. This is very bad for their legs, so they must exercise for thirty minutes every day.

After a day's work, astronauts relax. They may listen to music, read, watch films, play games, or talk to their friends and families on the radio. Sometimes they just enjoy floating in the air.

1.What does the underlined word "gravity" mean in Chinese?

2.Why do astronauts tie the sleeping bag to a wall?

3.What's the main idea of the passage?

Can you imagine astronauts' everyday life in space? They also need to eat,  sleep, exercise and relax. They do the same things as us, but they do them differently.
On Earth, we put food on a plate. Gravity holds the food down and keeps it on a place. But there is almost no gravity in space, so food can float （漂浮）away, and astronauts must eat carefully.
Sleeping is very different in space. Some astronauts like to float in the air, but most like to be in a sleeping bag. They tie the bag to a wall so that they won't float away at night.
Exercise is very important in space. On Earth,  your legs carry your body,  but in space, astronauts float, so they do not use their legs often. This is very bad for their legs, so they must exercise for thirty minutes every day.
After a day's work, astronauts relax. They may listen to music, read, watch films, play games, or talk to their friends and families on the radio. Sometimes they just enjoy floating in the air.

1. 1.

   What does the underlined word "gravity" mean in Chinese?

   1. A.
      平衡
   2. B.
      引力
   3. C.
      磁性
   4. D.
      重力
2. 2.

   Why do astronauts tie the sleeping bag to a wall?

   1. A.
      Because in that way they won't float away.
   2. B.
      Because that makes them sleep well.
   3. C.
      Because they can't get to sleep if they don't do that.
   4. D.
      Because the sleeping bag is not safe enough.
3. 3.

   What's the main idea of the passage?

   1. A.
      It is about the importance of gravity.
   2. B.
      It is about astronauts' everyday life in space.
   3. C.
      It is about the differences between space and Earth.
   4. D.
      It is about how to avoid （避免） floating away while sleeping.