---I called you at 4:00 yesterday afternoon, but nobody answered.
---Sorry, I ______ with my friends at that time.
A. had swum B. swam
C. would swim D. was swimming
The WHO has given some advice on to prevent us being infected(感染)with H7N9.
A. how B. what C. where D. when
When the parents arrived at the hall, the students _______ their projects.
A. have finish B. had finished
C. finished D. are finishing
Tom Sawyer let his friends _______ a long fence by playing a trick one afternoon.
A. paint B. to paint C. painting D. to painting
There are three English-books on the shelf, but ______ of them is mine.
A. both B. neither C. all D. none
The manager asked him if he ________for the extra work the next weekend.
A. had come B. will come C.would come D. came
