He commanded that all the gates _____when it was getting dark in case thieves came in .
| A．were shut | B．must be shut |
| C．could be shut | D．be shut |
The little girl walks as if she _________ an old woman.
| A．is | B．has been |
| C．was | D．Were |
Don't you think it a pity that John ______ have behaved roughly toward us?
| A．should | B．would |
| C．could | D．might |
In order to do something meaningful, it’s necessary that you _______ determine what is really important.
| A．must | B．will |
| C．need | D．should |
It is strange that such a thing ______ in your school．
| A．will happen | B．happens |
| C．should happen | D．happened |
—What a pity! Their experiment is a failure.
—They ________ better under more favorable conditions.
| A．should have done | B．could have done |
| C．must have done | D．may have done |