—I don't understand why you didn't go to the lecture yesterday afternoon.
—I'm so sorry. But I________ my homework.
A.had done B. was doing
C. would do D. am doing
I ________ to visit you later that day, but I had to phone and cancel.
A. come B. came
C. am coming D. was coming
I didn't think I'd like the movie, but actually it ________ pretty good.
A.has been B. was
C.had been D.would be
We are confident that the environment ________ by our further efforts to reduce pollution.
A.had been improved B.will be improved
C.is improved D.was improved
He was unhappy when he sold his guitar. After all,he________it for a very long time.
A.has had B.had had
C.has D.had
Hurry up,kids! The school bus ________ for us!
A. waits B. was waiting
C. waited D. is waiting
