Experts say walking is one of the best ways for a person to _____ healthy.
| A．preserve | B．stay | C．maintain | D．reserve |
She is making herself ill with _____ over her son's future.
| A．trouble | B．annoyance | C．disgust | D．worry |
The microphone enabled them to keep in touch, in other words, it made it _____ for them to contact each other.
| A．likely | B．capable | C．possible | D．probable |
In spite of the thunderstorm, the children slept _____ all night.
| A．densely | B．soundly | C．loudly | D．noisily |
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 |
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 |