Swan Lake is a famous ballet in four acts, ________ on a German fairy tale.
| A．basing | B．based | C．bases | D．to base |
If you __________ succeed, you must study as hard as you can.
| A．are going to | B．are to | C．will | D．should |
—Mike, why didn’t you come yesterday?
—I __________, but I had an unexpected visitor.
| A．had | B．would | C．did | D．was going to |
—What about the books?
—This kind of book __________ well.
| A．sell | B．are sold | C．is sold | D．sells |
Unfortunately, when I dropped in, Mr. Smith __________. So we only had time for a few words.
| A．has just left | B．was just leaving | C．had just left | D．just left |
By the time I got to the theatre, the play __________ for ten minutes.
| A．had been on | B．had begun | C．have been on | D．has begun |