Many people believe we are heading for environmental disaster _____we radically(彻底地) change the way we live.
| A．but | B．although | C．unless | D．until |
Through years of hard work, Mrs. Smith, who ____ as a secretary for five years, is general manager of the company now.
| A．serves | B．served | C．has served | D．had served |
The newly-discovered evidence led to the criminal ____ to five years in prison.
| A．to be sentenced | B．being sentenced | C．sentenced | D．be sentenced |
The discovery of the new drug is of great ____ to people who suffer from heart problems.
| A．appreciation | B．significance | C．satisfaction | D．guidance |
In the job interviews job applicants often find themselves asked unexpected questions, some very difficult ____.
| A．to be answered | B．to answer | C．being answered | D．answering |
The policeman kept his eyes________on the screen of the computer to identify the criminal's footprints.
| A．fixing | B．fixed | C．to fix | D．being fixed |