题目内容：

We live on Earth. 1. Think about this, what if we lived on the other planet? Several years ago, many people believed we could live on Mars. 2. Let’s compare them and think about which planet is more suitable to live on.

The temperature on the surface of Mars is -73℃—20℃. 20℃ is suitable for humans, and -73℃ is near the average temperature of the Antarctic (南极), 3. And we have made a real trip to Mars. It would take 6 months to fly to Mars by spaceship. However, 4. Of course, humans can live through this by living in buildings, where plants could be grown and used to produce oxygen.

Scientists said that Kepler-452b is an Earth-like planet. Because it is only about 1.5 times the diameter of Earth, circling a star very much like our own Sun Although we don’t know if we can live there, it lies on the right distance where water could exist (存在). 5. But it is too far from us. Using present technology, it would take 25.8 million years to get there. So far, we’ve no hope of getting there.

 

A. so temperature isn’t a problem on Mars.

B. But until recently, a planet- Kepler452 b has been found by NASA (美国家航空航天局).

C. And water is important to lives on Earth.

D. But our Earth is becoming more and more crowded and polluted.

E. Mars is made up of 95% carbon dioxide, which is not suitable to humans.