1.Do you know where the UFO comes from?
2.He asks whether you will go fishing on Sunday.
3.He asked how you can help pritoot the enviroment?
4.Could you tell us when the basketball was evented?
5.The teacher told us light travels faster than sound.(光比声音传播快.)
6.I cann't understand why you like computer so much.
7.we asked them whether they will pilnt trees on saturday or not.
8.We haven't decided where we shall go for the hiking.
这些根本不是打错的,故意的吧.大致就这些了,有些词你错得太离谱,所以不知道是什么.不过语法没错.