I ________ a topic for the composition, but haven’t decided yet.
| A．will think about | B．have been thinking about |
| C．had thought about | D．was thought about |
David is such a good boy _______ all the teachers like.
| A．that | B．who | C．as | D．whom |
The thief tried to break away from the policeman who ______ him, but failed.
| A．has held | B．had held |
| C．was holding | D．would hold |
The factory was built in a secret place, around ______ high mountains.
| A．which was | B．it was | C．which were | D．them were |
The telephone _______ three times in the last hour, and each time it ________ for my father.
| A．had rang； was | B．has rung； was |
| C．rang； has been | D．has been ringing； is |
The ______ has become extremely tense. A war could break out any time between the two sides.
| A．pollution | B．friendship |
| C．condition | D．situation |