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impossible;   discover;   different;   get;   close；call;   might;   although;   larger;   send

Lots of scientists believe that there’s life on other planets. Because of this, they keep doing research about the universe. They have sent astronauts to the moon. And they have 【小题1】the answer. There’s no life on the moon. Not long ago they 【小题2】 spaceships to Mars. There, they didn’t find life, either. And they found the environment of Mars was 【小题3】 from that of the earth. Then they knew it was 【小题4】 for people to live on Mars.

【小题5】 they haven’t received a message from other planets, they believe that their idea is right. Recently they have 【小题6】 a planet. It’s 【小题7】 Proxima Centauri. It’s very 【小题8】 to our earth. It is just over four light years away. Proxima Centauri is 【小题9】 than the earth. And there’s water on this planet. It 【小题10】 mean that life is possible there. Now scientists are studying this planet. Soon they will tell people the answer.