Why _______ you be so stubborn? You should think over my advice on this matter.
| A.may | B.shall | C.dare | D.must |
With a good __________ of Chinese, Helen was hired to do the task of communication with the Chinese company.
| A.program |
| B.command |
| C.guidance |
| D.ability |
The teacher commanded that the students __________ the classroom before he returned.
| A.didn't leave |
| B.wouldn't leave |
| C.needn't leave |
| D.shouldn't leave |
Before the tourists set off, they spent much time setting a limit __________ the expenses of the trip.
| A.in |
| B.for |
| C.to |
| D.about |
There is a limit __________ people's life, but no limit __________ the knowledge.
| A.on; to learn |
| B.to; to learn |
| C.on; learning |
| D.to; to learning |
Unfortunately, the research was limited __________ increasing economic profits,__________ protecting the environment.
| A.to; other than |
| B.by; rather than |
| C.to; rather than |
| D.by; more than |