Sometimes you can see the moon in the early morning. And sometimes you can see the moon in the sky at night. It's like a bright light in the dark sky. Sometimes it's full. And then it's not so full， and then you may not see it unless you pay more attention to it.
When we look at the moon， we can see some bright parts and some dark parts. This is because there are mountains on the moon.
There is no water on the moon. So there are no rivers there.
There is no air round the moon. So there are no trees or flowers there. There are no animals， birds or people there.
There is no life on the moon because there is no air or water there.
1. unless conj. 除非
2. pay more attention to 特别注意
3. part n. 部分
4. mountains n. 山、山脉
5. air n.空气、大气
6. life n.生命