Have you ever dreamed of staging a concert, ________ thousands of people are applauding and appreciating your music?
| A．at which | B．when |
| C．for which | D．which |
Large quantities of water ______and lots of fish died.
| A．has been polluted | B．were polluted |
| C．is polluted | D．was polluted |
When was it ______ you met Yao Ming in the street?
| A．as | B．if | C．while | D．that |
How happy we _______, if you had come with us to the party.
| A．could be | B．may have been |
| C．would have been | D．were |
It is required that no smoking ______ in the school.
| A．was allowed | B．be allowed |
| C．would be allowed | D．had been allowed |
The dress is not ______ for the formal party. You’d better find another one.
| A．appropriate | B．convenient | C．available | D．actual |