—The two people speak different languages and can not communicate with each other well.
—Oh，I see. That’s ________ misunderstanding occurs.
| A．when | B．what |
| C．which | D．why |
Don’t treat the vase as if it _______ made of steel.
| A．is | B．was |
| C．were | D．had been |
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 |