When Marx was in London, he _______ read at the library for hours.
| A．would | B．might | C．could | D．should |
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 |
With the audience __________ at her, the little girl felt nervous on the stage.
| A．staring |
| B．to stare |
| C．stare |
| D．stared |
Half the world's population __________ water shortages within 15 years according to the World Bank, just one of many recent alarming reports on the world's fresh water supply.
| A．are suffering |
| B．have been suffered |
| C．will suffer |
| D．were suffered |