Although they plant trees in this area every year, the tops of hills are still ______.
| A．blank | B．hollow | C．vacant | D．bare |
We are going to the theater tomorrow ______ all the tickets are sold out.
| A．when | B．unless |
| C．whether | D．because |
Once ______, the book will surely attract readers’ attention since it is related to people’s health.
| A．publishing | B．having published |
| C．published | D．to publish |
—I am worn out now. I stayed up last night to finish the report.
—Oh? You ______. The professor asked us to hand it in next week.
| A．needn’t have | B．wouldn’t have |
| C．couldn’t have | D．can’t have |
______ full preparations, Tony was quite confident about the coming interview.
| A．Make | B．Made |
| C．To make | D．Having made |
The whole class applauded wildly at the end of the speech, ______ greatly encouraged Bob.
| A．what | B．where | C．which | D．when |