_________ caused the accident is still a complete mystery.
| A．What | B．That |
| C．How | D．Where |
The ______ of air and water makes it impossible to live on the moon.
| A．presence | B．absence | C．dependence | D．evidence |
— Have you seen Shirley since she moved away?— Yes. I’ve seen her several times. She comes back to visit us ______.
| A．at any moment | B．from time to time |
C．in no time | D．sooner or later |
Xinhua said the landslide not only _____ power and communications, it also caused death.
| A．cut down | B．cut out | C．cut up | D．cut off |
— I’ve never found a better job.
— ______.
| A．Congratulations | B．You have really bad luck |
| C．I am sorry to hear that | D．Don’t be worried |
He had to _______ paying the bills because of a lack of money.
| A．put down | B．put off | C．put out | D．put aside |