Do you know _______ World Water Day is?－On March 22nd.

Lucy doesn’t mind lending you her dictionary.—I think she doesn’t, but I ________do so. I’ve already borrowed one.

You must look around when you go _____ the street.[ ]

Don’t forget _________ your homework, John. — OK, I’ll do it right now.

The story is very interesting, so most of us like it.