The chairman thought _____ necessary to invite Professor Smith to speak at the meeting.
| A．those | B．that | C．it | D．this |
About 187 passengers were reported _____the shipwreck which happened last month.
| A．to have been survived | B．having survived |
| C．to have survived | D．to survive |
Once new difficulties ________in your work, it’s always important to use your brains.
| A．arise | B．raise | C．arouse | D．rise |
--How are your recent trip to Sichuan?
—I’veneverhad ______ onebefore.
| A．apleasant | B．amorepleasant |
| C．amostpleasant | D．themostpleasant |
Shy people often avoid situationswould force them into close contact with other people．
| A．which | B．where | C．when | D．what |
—How long do you think it will be______man can finally solve the problem of cancer?
—Well，it depends
| A．when | B．until | C．after | D．before |