Sam _____ some knowledge of the computer just by watching others working on it．
| A．brought up | B．looked up | C．picked up | D．set up |
—Is Nick coming by train?
—He should, but he ________ not. He likes driving his car.
| A．must | B．may |
| C．can | D．need |
—In case anyone ________ come in my absence, tell him I will be back soon.
—Sure, I will.
| A．would | B．should |
| C．will | D．shall |
John ________ yet, or he would have telephoned me.
| A．mustn't have arrived | B．shouldn't have arrived |
| C．needn't have arrived | D．can't have arrived |
—She looks very happy. She ________ have passed the exam.
—I guess so. It's not difficult after all.
| A．should | B．must |
| C．could | D．might |
A survey has shown that 40% of those killed in traffic accidents ________ if they had been wearing seat belts.
| A．should have been saved |
| B．must have been saved |
| C．need have been saved |
| D．could have been saved |