It is well known to us all ____ China sent up a manned spaceship to outer space successfully last year.
Mrs. Brown was much disappointed to see the washing machine she had _____ went wrong again.
We used to work in the same office and we _________ have coffee together.
I _____ to take a holiday this summer, but I had to change my plan .
-I heard Back Street would sing at the New Theater. -Where did you _____?
-Are you satisfied with her answer? -Not at all. It couldn’t have been _____.