2．Listen！There is somebody k__________ at the door．

1．The s__________ on the teacher’s face showed that she was pleased with us．

35．The room needs ___________ for three people．

　 A．to be big enough　　 B．to big enough　 C．to be enough big　　 D．enough big to be

34．I like music ___________ I can dance to．

　 A．who　　 B．what　　 C．when　　 D．that

33．It took me half an hour ___________ my homework．

　 A．did　　 B．do　　 C．doing　　 D．to do