Beijing was attacked by such a terrible sandstorm __________few citizens has ever experienced before.
| A．where | B．as | C．when | D．which |
—I really can’t thank you enough
—．
| A．With pleasure | B．I’m glad to have been of help |
| C．No problem | D．That’s the most I could do |
—What’s the matter with Tim?
—Oh, Tim’s cellphone was left in a taxi accidentally, never ____ again.
| A．to find | B．to be found | C．finding | D．being found |
It was believed that things would get worse, but ____ it is they are getting better.
| A．before | B．after | C．because | D．as |
I ____ to go for a walk, but someone called and I couldn’t get away.
| A．was planning | B．planned | C．had planned | D．would plan |
—The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?
—____ my students have a try?
| A．Shall | B．Must | C．Will | D．May |