题目内容：

For people who are interested in space, nothing is more exciting than the idea of living on other planets. That might be why the movie The Martian is so popular. It shows an astronaut living on Mars. But would it really be possible to live on the Red Planet?

While the idea of living on Mars is great, the reality does not look as good. Mars does not have a friendly air for humans. There is very little oxygen(氧气) there. And because it's far from the sun, it is also very cold. The temperature on Mars can be ­62 on average. This is much too cold for humans.

However, scientists say it might be possible to live there even without a good air. Daytime on Mars is almost the same as Earth's. It means there's enough sunlight to grow plants inside safe buildings. However, they would have to grow in soil from Earth. Mars does not have a strong enough air to stop the radiation(辐射) coming from space, which makes it dangerous to grow things in the soil.

The radiation also causes problems for our health. One way we could live there would be to build homes under ground or within the rocks on the planet. This would give humans the protection(保护) from the radiation and also some heat.

When could we live on Mars? NASA is hoping to make some progress within the next 20 years.

1.Which of the following about Mars is TRUE?

A. Its air is good for humans.    B. It has enough oxygen on Mars.

C. It's a little colder than Earth.    D. It's not close to the sun.

2.Why is it possible to grow plants on Mars?

A. Because there is enough sunlight.

B. Because the soil is good on Mars.

C. Because it has little oxygen there.

D. Because it has the strong radiation.

3.What's the passage mainly about?

A. How to grow plants on Mars.

B. How to live on Mars without danger.

C. How to keep warm on Mars.

D. How to improve the air on Mars.