题目内容：

选词填空：根据对话内容，用方框中所给单词的适当形式填空，每词限用一次。

water no Earth it for
 

Bill: I saw a great programme on TV about space yesterday evening.

Tony: What is1.about?

Bill: Scientists have discovered2.on Mars.

Tony: Really? That’s very fantastic. Have they discovered life on Mars?

Bill: Well, they’re looking3.life but they haven’t found anything yet.

Tony: I know there’s4.life on the moon.

Bill: Yes, that’s right. So far there’s only life on5..

Tony: Are we alone with so many stars in the universe?

Bill: I am interested in it, so I want to be a scientist when I grow up.

Tony: I wish you will.