22. Food aid______ is the key to______ the problem _______ now.
| A．only, solve, discussed | B．alone, solving, being discussed |
| C．merely, solving, being discussed | D．alone, solve, being discussed |
We arranged to meet at 8:00, but she never ______.
| A．turned down | B．turned off | C．turned over | D．turned up |
Missing the flight means _______ for another three hours.
| A．waiting | B．to wait | C．wait | D．to be waiting |
After I had finished eating, he advise me ______ immediately.
| A．set off | B．set aside | C．set down | D．set about |
-----This returned Chinese scholar has become one of the top experts in this field.
-----Yes, I know him very well. He _____ in Africa with wild animals for eight years.
| A．is working | B．had worked | C．worked | D．has been working |
All________made______possible for China to succeed in carrying on its reforms and open-door policy.
| A．what happened; it | B．what happened; that | C．that happened; it | D．that happened; that |