---The air pollution is terrible.
---It will be worse _______ we take action to protect the environment.
| A． if | B．unless |
| C．until | D．When |
—I’m busy with my schoolwork these days.
—That’s great! You won’t get good grades ______ you work hard.
| A．if | B．because |
| C．unless | D．after |
—Whose pencil box is this?
—It _____ be Tom’s. It has his name on it.
| A．must | B．may |
| C．might | D．can’t |
—______ do you surf the Internet?
—About twice a week.
| A．How soon | B．How often |
| C．How long | D．How far |
—Do you often play ______ tennis after school?
—No, I don’t like sports. I often play______ guitar.
| A．a, the | B．the, / | C．/, the | D．the, a |
— I didn’ t expect to see you studying at the library so early in the morning.
—, huh?
| A．Every dog has its day |
| B．Many hands make light work |
| C．The early bird catches the worm |
| D．Too many cooks spoil the broth |