On September 25，2008，the Shenzhou-7 spacecraft carrying Zhai Zhigang，Liu Boming and Jing Haipeng successfully flew into space by a Long March Ⅱ-F rocket．And one of the astronauts，Zhai Zhigang，made a spacewalk this time．This was a major event in China．

Maybe you will ask，“How does a rocket fly?” If you want to know，get a balloon（气球）and then blow it up until it is quite big．Do not tie up（系紧）the neck of the balloon．Let go! The balloon will fly off through the air vel3t quickly．The air inside the balloon tries to get out．It rushes out through the neck of the balloon，and pushes（推）the balloon through the air．It does not need wings like an airplane．This is how a rocket works．A rocket is not made of rubber like a balloon，of course．It is made of metal（金属）．The metal must not be heavy，but it must be very strong．There is air 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 sky．

People hope to know more about space．Rocket can fly into space．One day rockets may be able to go anywhere in space．

1．The underlined words “major event'” might mean “_________”．

A．主修课题            B．专研项目             C．重大事件            D．重要比赛

2．An astronaut _________．It was a most important thing in China．

A．walked in space                                         B．slept in space

C．flew in space                                             D．jumped onto the moon

3．The balloon will fly off if the _________ inside it gets out．

A．neck                    B．wing                    C．water                     D．air

4．The metal of the rocket is _________．

A．heavy and strong                                     B．light and strong

C．heavy but not strong                                  D．light but not strong

5．According to the passage，which of the following is TRUE?

A．The air inside the rocket is cool．

B．Now rockets are able to arrive anywhere in space．

C．A rocket flies in the same way as a flying balloon．

D．The neck of the balloon pushes the balloon through the air．