. I think you must be mistaken about seeing him at the theatre； I’m sure he _____ abroad all week.
| A．is | B．was |
| C．has been | D．had been |
After retiring，he was recommended to gardening as a hobby．
| A．take up | B．take on | C．take off | D．take away |
—You ought to have called him yesterday．
—Yes，I know I．
| A．ought to | B．have to | C．should have | D．must have |
Persons under 16 not be employed in our country．
| A．shall | B．can | C．may | D．will |
—I’m sorry I have failed again in the math exam．
—？You’ve been working hard at the subject．
| A．How | B．How come | C．Why not | D．When |
Everybody had an impression she was a good match for the young man．
| A．that | B．which | C．with which | D．for which |