The astronauts working in these towns wear their space suit and also do everything they would really have to carry out if they ever go to Mars in the future.
But Mars would be like Earth, a temporary（临时的） place for humans. When the Sun starts swallowing up(吞掉) the planets, Mars will disappear only hours after Earth. So Mars only seems to be the ideal place to spread the human beings. It is also a good location to send humans if ever there is a disaster on Earth. By saying disaster, I mean asteroids(小行星) hitting and things like that.
If we humans do not want to disappear when Earth or Mars gets swallowed up, we will have to go and live beyond the solar system. But are there any planets outside our solar system prepared to support life? Astronomers’ answer is:
“If Earth can support life, why can’t other planets do the same too? Astronomers have already discovered a Jupiter(木星)- like planet orbiting a Sun-like star, so why not an Earth-like planet orbiting a Sun-like star?
To achieve this goal though, many other problems have to be taken into consideration. How do we transform(改造) a dusty planet like Mars into one more or less like our Earth? How should we go on? There is still a long way to go.

1.
The “Mars town” mentioned in the passage is ___________
1. A.
  a research base on Mars.
2. B.
  an experimental lab built on Earth.
3. C.
  a strange place on Mars .
4. D.
  a town existing in scientists’ imagination
2.
We can know from the passage that astronomers probably think ____________
1. A.
  it is impossible to transport humans to other planets.
2. B.
  there may be an Earth-like planet outside the solar system
3. C.
  humans will move to the new-found Jupiter-like planet
4. D.
  there’s no need for humans to move beyond the solar system.
3.
Why would Mars only be a temporary(临时) place for humans?
1. A.
  The conditions there would be too hard for the human beings
2. B.
  There would be more disasters like asteroids hitting.
3. C.
  It would disappear when Earth disappeared.
4. D.
  It would be too hot to live on.
4.
The underlined word “orbiting” in the fifth paragraph is closest in meaning to “________”
1. A.
  moving around
2. B.
  getting close to
3. C.
  passing by quickly
4. D.
  going through
5.
Which of the following would be the best title for this passage?
1. A.
  Mars Town
2. B.
  Living on Mars
3. C.
  The Future of Earth
4. D.
  Where to live in the Future