I told him what I was surprised his attitude towards the old.
| A．were | B．at were | C．was | D．at was |
—May I smoke here?
—If you _______, choose a seat in the smoking section.
| A．should | B．could |
| C．may | D．must |
—Can we ski on this mountain?
—Of course.However, at no time _______ you do so alone.
| A．could | B．might |
| C．need | D．must |
He _______ have completed his work；otherwise, he wouldn’t be enjoying himself by the seaside.
| A．should | B．must |
| C．wouldn’t | D．can’t |
He must have been late for the conference yesterday, _______?
| A．didn’t he | B．hasn’t he |
| C．mustn’t he | D．wasn’t he |
He _______ more visits to his parents.He has been regretting not doing so since they passed away.
| A．should pay |
| B．would pay |
| C．should have paid |
| D．would have paid |