阅读理解
Rockets(火箭)can fly far out into space.Rockets with men inside them have already reached the moon in the USA and Russia.Several rockets without men inside them have been sent to other worlds much farther away.On Nov.7, 2007, China’s first lunar probe, Chang’e I, successfully has completed its 1,580,000 km flying journey to the moon.

I am sure that you are asking ‘How does a rocket fly?’ If you want to know, get a balloon and then blow it up, until it is quite big.Do not tie up the neck of the balloon, let it go.The balloon will fly off through the air very quickly.The air inside the balloon tries to get out.It rushes out through the neck of the balloon and this pushes the balloon through the air.
This is how a rocket works.Of course, the rocket is made of metal.The metal must not be heavy but it must be very strong.There is gas inside the rocket, which is made very hot.When it rushes out of the end of the rocket, the rocket is pushed up into the air.The jet velocity(喷射速度)is always faster than the flying speed.
We’re sure that one day rockets with man may be able to go anywhere in space.