1.What he wants to tell us is not clear. 他要跟我们说什么，还不清楚。
2.Whether there is life on the moon is an interesting question. 月球上有没有生命是个有趣的问题。
He said that Tom is good boy.宾语从句
what he said is right.主语从句。
The reason is that the weather was bad at that time.表语从句。
I will tell you the truth when you come.状语从句
The man who had lost his bag was very angry.定语从句。
带有从句的句子和主句一起构成复合句。
