My mother is sleeping .Don’t _________.
Please knock at the door ________ you come into the room.
A tourist will easily lose his way in Beijing ______ he has a map or a guide.
Be quick, ___we’ll be late for school.
--- I won’t go to the party tonight.--- ______ you told me you would. What’s the matter?
Hold on to your dreams, _____ one day they may come true.