. We ______________ last night, but we went to the concert instead.
| A．must have studied | B．might study |
| C．should have studied | D．would study |
Mr Smith， together with his children， ____arrived.
| A．are | B．has | C．is | D．have |
About 20 percent of the work ____done yesterday.
| A．are | B．is | C．were | D．was |
Ten thousand dollars _____quite a large sum.
| A．are | B．is | C．were | D．have |
This is one of the best novels that ____appeared this year.
| A．have been | B．has | C．had been | D．have |
Most of his spare time ____spent in reading.
| A．are | B．were | C．was | D．have been |