The rockets take astronauts and man-made satellites into space. The satellites are used for communication, weather monitoring and research. But how do satellites stay up without falling down?There are 题目和参考答案——青夏教育精英家教网—

题目内容

The rockets take astronauts and man-made satellites into space. The satellites are used for communication, weather monitoring and research. But how do satellites stay up without falling down?
There are two opposite forces (力量) acting on the satellite. One of them is the force of gravitation (地心引力), which tries to pull the satellite towards the earth. The other force is created by the rotation (旋转) of the satellite around the earth. This force tries to take the satellite away from the earth. With these two forces, the satellite goes round and round. The gravitational pull of the earth (the force which pulls everything towards the ground) is like a rope which keeps the satellite from flying away.
Everything that goes up has to come down. It is only a matter of time before a satellite comes back to the earth. As time goes by, the satellite loses its speed, which makes the gravitational pull stronger than the force pulling it away. This makes the satellite crash (坠落) down to the earth.
【小题1】Which of the following uses of satellites is NOT mentioned?

A．communication

B．monitoring the weather condition

C．doing some research

D．taking pictures

【小题2】The force that pulls the satellite towards the earth is created by ________.

A．the earth

B．the satellite itself

C．the rotation of the satellite

D．the rope

【小题3】Why can’t the satellites fly away?

A．Because of the force from the earth.

B．Because the satellite is too big.

C．Because of the force created by the rotation of the satellite around the earth.

D．Because people on earth have made ropes to tie the satellites tightly.

【小题4】The satellite will finally crashes down to the earth ________.

A．when it flies faster

B．when its speed slows down

C．when people cut the rope

D．when there is no electricity in it

【小题5】Which of the following is TRUE according to the passage?

A．There are four forces acting on the satellite.

B．The force of gravitation makes the satellite go round and round.

C．As time goes by, the satellite will finally fall down.

D．The satellite will stay in space forever.

【小题1】D
【小题2】A
【小题3】A
【小题4】B
【小题5】C

解析

练习册系列答案

阅读理解（二）（本题共5小题；每小题2分，满分10分）
阅读下列短文回答问题：
The most unusual museum in London is the Science Museum. In most museums, there’s no shouting and no running, and you aren’t allowed to touch the exhibits. But the Science Museum is different… because it’s noisy ! People talk about what they can see and do there, and some of the machines are noisy as well. Visiting the Science Museum is fun and it’s a great way to learn about science because you can work things out and try out ideas.
When I visit the Science Museum, I go to the Launch Pad. This is my favorite room because you can do physics experiments. For example, if you want to fill a bag with falling sand, you have to move a kind of truck on wheels into the correct position. I also go to the Rocket Show. You can learn how we travel into space and back again.
Then I go upstairs to the Human and Nature room. You can compare your speed with animals there. You hear a noise and push a button. If you aren’t fast enough, the lion catches you! I’m faster than all my friends, but the lion still catches me.
You can do a lot of things in this museum, but you have to obey some rules as well. For example, you mustn’t take photos of the exhibits in the museum. But you can buy postcards of them in the museum shops.
Above all, the Science Museum is free. That means you can drop in for a few minutes or you can stay as long as you like – it’s open every day, from 10 am to 6 pm. So if you ever go to London, make sure you visit the Science Museum. It’s my favorite museum in the whole world.
【小题1】Where does Tony go first when he visits the Science Museum?
【小题2】What can you try out in the Human and Nature room?
【小题3】How much does it cost to go in the Science Museum?
【小题4】How long can you stay at the Science Museum ?
【小题5】What does the writer think of the Science Museum?

Scientists are very interested in the Universe，and they always want to know more about it. Years ago they knew many things about the moon. They knew how big it is and how far away it is from the earth. But they wanted to know more about it. They thought the best way was to send men to the moon. The moon is about 384,000 kilometers away from the earth. A plane cannot fly to the moon because the air reaches only 240 kilometers away from the earth. But something can fly even when there is no air. That is a rocket(火箭)
How does a rocket fly? There is gas（气体） in the rocket. When the gas is made very hot inside the rocket, it will rush out of the end of the rocket, so it can make the rocket fly up into the sky. Rockets can fly out into space. Rockets with men in them have been to the moon. Several rockets without men in them have flown to another planet(行星) much farther away than the moon. One day, rockets may be able to go to any place in space.
【小题1】Scientists knew ____________ the moon is.
A: how far    B: how big    C: how old    D: both A and B
【小题2】The earth is about 384,000 kilometers away from the _____.
A: space    B: universe    C: sun   D: moon
【小题3】A plane cannot fly to the moon because ___________
A: there is no air above 240 kilometers away from the earth.
B: there is no gas in the plane
C: the plane is not strong enough
D: the plane can not fly a long way
【小题4】The hot gas in the rocket is used for___________
A: keeping the air in the rocket fresh(新鲜的)
B: Keeping the men in the rocket warm
C: making the rocket fly up.
D: cooking food for the men
【小题5】What is the writer’s attitude(态度) to the universe’s future.
A: Realistic(现实的)        B: Imaginative(幻想的)
C: Confident(有信心的)      D: Sad

Scientists are very interested in the Universe，and they always want to know more about it. Years ago they knew many things about the moon. They knew how big it is and how far away it is from the earth. But they wanted to know more about it. They thought the best way was to send men to the moon. The moon is about 384,000 kilometers away from the earth. A plane cannot fly to the moon because the air reaches only 240 kilometers away from the earth. But something can fly even when there is no air. That is a rocket(火箭)
How does a rocket fly? There is gas（气体） in the rocket. When the gas is made very hot inside the rocket, it will rush out of the end of the rocket, so it can make the rocket fly up into the sky. Rockets can fly out into space. Rockets with men in them have been to the moon. Several rockets without men in them have flown to another planet(行星) much farther away than the moon. One day, rockets may be able to go to any place in space.
【小题1】Scientists knew ____________ the moon is.
A: how far    B: how big    C: how old    D: both A and B
【小题2】 The earth is about 384,000 kilometres away from the _____.
A: space    B: universe    C: sun   D: moon
【小题3】A plane cannot fly to the moon because ___________
A: there is no air above 240 kilometers away from the earth.
B: there is no gas in the plane
C: the plane is not strong enough
D: the plane can not fly a long way
【小题4】 The hot gas in the rocket is used for___________
A: keeping the air in the rocket fresh(新鲜的)
B: Keeping the men in the rocket warm
C: making the rocket fly up.
D: cooking food for the men
【小题5】 What is the writer’s attitude(态度) to the universe’s future.
A: Realistic(现实的)         B: Imaginative(幻想的)
C: Confident(有信心的)      D: Sad

The most unusual museum in London is the Science Museum. In most museums, there’s no shouting and no running, and you aren’t allowed to touch the exhibits(展品). But the Science Museum is different, because it’s noisy! People talk about what they can see and do there, and some of the machines are noisy as well. Visiting the Science Museum is fun and it’s a great way to learn about science because you can work things out and try out ideas.

When I visit the Science Museum, I go to the Launch Pad. This is my favourite room because you can do physics experiments. For example, if you want to fill a bag with falling sand, you have to move a kind of truck on wheels into the correct position. I also go to the Rocket Show. You can learn how we travel into space and back again.

Then I go upstairs to Human and Nature room. You can compare your speed with animals there. You hear a noise and push a button(按钮). If you aren’t fast enough, the lion catches you! I’m faster than all my friends, but the lion still catches me.

There are also rooms on transport, the environment and space technology, as well as maths, physics and chemistry.

You can do a lot of things in this museum, but you have to obey some rules as well. For example, you mustn’t take photos of the exhibits in the museum. But you can buy postcards of them in the museum shops.

Above all, the Science Museum is free. That means you can drop in for a few minutes or you can stay as long as you like—it’s open every day, from 10 am to 6 pm. So if you ever go to London, make sure you visit the Science Museum. It’s my favourite museum in the whole world.

1. What is the writer’s favourite room?

A. The Launch Pad.

B. The rooms on space technology.

C. The Human and Nature room.

D. The Rocket Show.

2. What can’t you do in the Science Museum?

A. Touch the machines.

B. Do chemistry experiments.

C. Take photos of the exhibits.

D. Talk loudly about what you see.

3. How much does it cost to go into the Science Museum?

A. $10 for adults. B. $6 for children.

C. Only free for children. D. Free for everyone.

4. How long can you stay at the Science Museum?

A. 6 hours. B. 8 hours. C. 10 hours. D.12hours.

5. In what way is the Science Museum different from other museums?

A. We can see a lot of exhibits in the Science Museum.

B. People can talk to each other in the Science Museum.

C. There’s no shouting and no running in the Science Museum.

D. You can work things out and try out your ideas in the Science Museum.

试题分类