You should have ____ good knowledge of English if you want to find a job here. Because English is the working language in_______ most international trade centers.
| A．不填；the | B．不填；不填 | C．a; 不填 | D．a; the |
We didn't know his telephone number, otherwise we _________ him.
| A．would have telephoned | B．must have telephoned |
| C．would telephone | D．had telephoned |
It was essential that the application forms ___________ back before the deadline .
| A．must be sent | B．would be sent |
| C．be sent | D．were sent |
_____________ cease（终止） advertising, prices would be significantly reduced.
| A．Were they to | B．Could they |
| C．If they | D．Would they |
Much labor would have been saved if the electronic computers_____________ before.
| A．had invented | B．were invented |
| C．should have been invented | D．had been invented |
There was a(n)________silence in the live interview，when no one knew what to say to the audience.
| A．ashamed | B．disappointed | C．desperate | D．awkward |