题目内容：

    Scientists are very interested in the universe and they always want to know more about it.Years ago they knew many things about the _______. They knew how big it was and _______ it was from the earth. _______ they still wanted to know more. They thought the _______ way was to send _______ to the moon. The moon is about 384,000 kilometres away from the earth. A plane cannot fly to the moon because the _______ reaches only 240 kilometres away from the earth. But _______ can fly even when there is no air. That is rocket.

How can 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(系紧)the neck of the balloon, but 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 _______ the neck of the balloon and this pushes the balloon through the air. It does not need wings like a plane.

There is gas(气体) in the rocket. So it can fly out into _______. Rockets with men in them have been to the moon. Several rockets have already flown to ________ planet much farther away than the moon. One day, rockets may be able to go to any place in space.

1.A.star B.moon C.sun D.planet

2.

A.how much B.how long

C.how many D.how far

3.

A.So B.And

C.But D.Or

4.

A.worst B.best

C.secret D.correct

5.

A.teachers B.men

C.animals D.computers

6.

A.air B.light

C.Jupiter D.Mars

7.

A.anything B.nothing

C.something D.none

8.

A.by B.on

C.from D.through

9.

A.space B.air

C.cloud D.station

10.

A.the others B.another

C.the other D.others