Have you ever a speaking competition?
| A．meet | B．enter | C．entered | D．joined |
John didn’t give up looking for a job __________ he got an offer from a German company.
| A．until | B．since |
| C．because | D．if |
— Would you like to go to the cartoon show with me?
— It sounds like fun, ______I’m too busy.
| A．so | B．for |
| C．or | D．but |
All passengers______go through safety check before they take a plane.
| A．can | B．may |
| C．must | D．ought |
_____ carefully, Michael! There’s a school ahead.
| A．Drive | B．To drive |
| C．Drove | D．Driving |
Air pollution has become__________ than ever before. We must do something to stop it.
| A．serious | B．more serious |
| C．most serious | D．the most serious |