We can never expect____bluer sky unless we create____ less polluted world.
| A．a; a | B．a; the |
| C．the; a | D．the; the |
There have been demands for the prime minister that he ______ office since the incident happened.
| A．leaves | B．left | C．will leave | D．leave |
Never before _____seen anybody who can play tennis as well as Robert.
| A．had she | B．she had | C．has she | D．she has |
He’s got himself into a dangerous situation he is likely to be accused of meeting someone.
| A．where | B．which | C．while | D．why |
He's late, __is often the case.
| A．as | B．what | C．it | D．this |
As soon as all the chairs are _______, we can let the people _______ outside enter.
| A．in the place; waiting | B．in place; waiting |
| C．in the place; waited | D．in place; waited |