7．Schools across China are expected to hire 50,000 college graduates this year as short-term teachers __________increase job opportunities.
| A．help | B．to have helped | C．to help | D．having helped |
Sit down, Emma. You will only make yourself more tired，__________ on your feet.
| A．to keep |
| B．keeping |
| C．having kept |
| D．to have kept |
No one is permitted __________ the room until the chairman declares the end of the conference.
| A．leave |
| B．to leave |
| C．leaving |
| D．left |
Our English teacher raised her voice to make herself __________.
| A．hear |
| B．to hear |
| C．heard |
| D．hearing |
Lisa was punished by her mother because she went out to play __________ her homework unfinished.
| A．with |
| B．before |
| C．after |
| D．of |
With the word “PM2. 5” constantly __________ in media reports, you might be wondering what on earth it means.
| A．appeared |
| B．appearing |
| C．to appear |
| D．being appeared |