________hard before, Tom is afraid of failing in the exam.
| A．Having been worked | B．Not to have worked |
| C．Having never worked | D．Never have worked |
Scientists have to work hard to keep _____ with modern discoveries and developments.
| A．company | B．track | C．touch | D．pace |
She _____ the temptation to buy a coat she could not afford.
| A．challenged | B．obstructed | C．contradicted | D．resisted |
. He put in a special _____ for an extra day's holiday so that he could attend his daughter's wedding.
| A．request | B．demand | C．inquiry | D．proposal |
It was decided to _____ the search when there was no hope of finding the missing girl alive.
| A．call off | B．take up | C．keep off | D．ring up |
The Prime Minister refused to comment on the rumor that he had planned to _____.
| A．discharge | B．dismiss | C．resign | D．resume |