题目内容
Scientists have always wanted to know more about the universe.
Years ago they knew many things about the moon. They knew how big it was and how far away it was 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 far 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.
根据短文内容,选择正确答案
1.Scientists have known ________ the moon is.
[ ]
2.The earth is about 384,000 kilometers away from the ________.
[ ]
3.A plane cannot fly to the moon because ________.
[ ]
A.there is no air 240 kilometers above from the earth
B.there is no gas in the plane
C.the plane is not strong enough
D.the plane must be driven by a man
4.The hot gas in the rocket is used for ________.
[ ]
A.keeping the air in the rocket fresh(清新的)
B.keeping the men in the rocket warm
C.making the rocket fly up
D.cooking food for the men
5.Several rockets without men in them have flown to ________.
[ ]
A.the stars
B.the satellites of the sun
C.the sun
D.another planet of the sun
Now satellites are helping to forecast the weather. They are in space, and they can reach any part of the world. The satellites take pictures of the atmosphere(大气), because this is where the weather forms. They send these pictures to the weather stations. So meteorologists(气象学家)can see the weather of any part of the world. From the pictures, the scientists can often say how the weather will change.
Today, nearly five hundred weather stations in sixty countries receive satellite pictures. When they receive new pictures, the meteorologists compare them with earlier ones. Perhaps they may find that the clouds have changed during the last few hours. This may mean that the weather on the ground may soon change, too. In their next weather forecast, the meteorologists can say this.
So the weather satellites are a great help to the meteorologists. Before satellites were invented, the scientists could forecast the weather for about 24 or 48 hours. Now they can make good forecasts for three or five days. Soon, perhaps, they may be able to forecast the weather for a week or more ahead(提前).
1.Satellites travel ___________.
A.in space |
B.in the atmosphere |
C.above the ground |
D.above space |
2. Why do we use the weather satellites to take pictures of the atmosphere?
Because ________.
A.the weather satellites can do it easily |
B.clouds form there |
C.the weather forms there |
D.the pictures can forecast the weather |
3.Meteorologists forecast the weather ________.
A.when they have received satellite pictures |
B.after they have compared new satellite pictures with earlier ones |
C.before they received satellite pictures |
D.during they study satellite pictures |
4.Maybe we’ll soon be able to forecast the weather for ________.
A.one day |
B.two days |
C.five days |
D.seven days or even longer |
5.The main idea of this passage is that satellites are now used in ______.
A.taking pictures of the atmosphere |
B.receiving pictures of the atmosphere |
C.doing other work in many ways |
D.weather forecasting |