As space science develops, man has learned more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger as well as success.
Scientists have found out that radiation (辐射) is the greatest danger to spacemen 'in space. When spacemen are working in space, they are in danger of radiation from the sun and other stars, which is bad for their health. The damage (危害) done by radiation won't be discovered until their children or even grandchildren are born. Some special medicine may work a little, but no really helpful medicine has been found so far.
Space rubbish is also thought a great danger to spacemen. It's reported that there are 9, 000 man-made things flying in space. About 300% of these are satellites  (卫星) , 10% are spaceships, and the rest are space rubbish. An explosion (爆炸)  in 1996 made a cloud of 300, 000 fragments (碎片), each at least 4mm in size, and even a small piece of these knocked against a spaceship window and did some damage. Scientists are watching and reporting any possible danger all the time. They are working to deal with space rubbish.
Although space is really dangerous, it interests everyone on the earth. In the near future, it may become usual for people to spend a few days in a space hotel. We may even choose to leave the earth and live in space in a few years. So we should care for space and do something to help improve the space environment
shows the man-made things in space in the correct way.

Space rubbish in space and the radiation from the sun and other stars are harmful to_______.

A．spacemen working in space	B．people only on the earth
C．all the people except children	D．all the spacemen

The passage talks about_______ kinds of danger in space.

A．two

B．three

C．four

D．five

Which of the following about the passage is TRUE?

A．Every one of us can make a trip to space in ten years.

B．Scientists have found out ways to solve any problems in space.

C．The harm of the radiation may be found in the spacemen's children.

D．Space is really dangerous, so it doesn't interest anyone on the earth.