I have to finish my homework first _____ cleaning up the room.[ ]

I often dream _ _ my mother.I miss her very much.[ ]

Look at my new digital camera. I bought it _____ June 1, Children’s Day.—Wow, how nice![ ]

If Li Lei __________ tomorrow, I’ll call him.[ ]

Some people waste too much water. They don’t believe that it can__________some day.