— You were out when I dropped in at your house.
— Oh, I _______ for a friend from England at the airport.
| A．was waiting | B．had waited | C．am waiting | D．have waited |
—Did you visit the famous museum?
—No.
We ________ it, but we spent too much time shopping.
| A．could have visited | B．must have visited |
| C．can't have visited | D．shouldn't have visited |
We’ll pay a ______visit to the beautiful city if we have enough time.
| A．a four-days | B．a four-day | C．four days | D．a four day |
Our company forbids ______, that is to say, we are not allowed ______here.
| A．to smoke; to smoke | B．smoking; smoking |
| C．smoking; to smoke | D．to smoke; smoking |
It was not rare in ______that 
people in ______fifties went to university for further education.
| A．1980s; their | B．the 1980s; the | C．the 1980s; their | D．1980s; the |
Yesterday my car suddenly ______on my way to work.
| A．broke up | B．broke out | C．broke in | D．broke down |