Is this the reason _______ at the meeting for his carelessness in his work?
| A．he explained | B．what he explained | C．how he explained | D．why he explained |
He pretended _______ when his mother stepped into his room.
| A．to study | B．studying |
| C．to have studied | D．to be studying |
Johnny, you ______ play with the knife; you _____ hurt yourself.
| A．wont; cant | B．mustn’t; may |
| C．shouldn’t; must | D．cant; shouldn’t |
Since 1949, the peoples living standard _______, causing a big _______ in population.
| A．has been raised; rise | B．has been rose; raise |
| C．has raised; rise | D．has raised; rose |
______ has already been pointed out, grammar is not a set of dead rules.
| A．As | B．It | C．That | D．Which |
There is a mountain ________ the top is always covered with snow.
| A．of that | B．of which | C．whose | D．that |