His first concert was well ____ and so all the tickets of his second one were sold out quickly.
| A．believed | B．received | C．agreed | D．admitted |
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 |