阅读短文,It's a sunny day.Little Water Drop sleeps in a river.He

阅读短文,
It's a sunny day.Little Water Drop sleeps in a river.He wakes up.He feels very hot.It may be cooler up in the sky,he thinks.Then he becomes vapour.He goes up.Little Water Drop goes higher and higher.He meets many other little water drops.They go up together and become a cloud.Little Water Drop becomes very heavy.Little Water Drop and some of his friends fall down into a lake,and the rain becomes.
1.How can the water in the lake become vapour?
2.Where does the cloud come from?
3.Where does the rain come from?