3.of the rivers in this city have been polluted.

52.According to the art dealer, the paintingto go for at least a million dollars.

51.一The window is dirty.一I know. It for weeks.

50.When Mark opened the door, he saw a woman standing there. Heher before.

49.The vegetables didn＇t taste very good. Theytoo long.

48.The studentshomework busily when Miss Brown went back to get the book shein theclassroom.

47.This English novelmore easily than that one.

46.Having no key to the door, the poor boyanxiously in the rain for one and a half hours, and hewould wait till his mother arrived.

45.Will you please give him the key as soon as he?

44.Thank you for telling me that. I really.

43.I hope youall the factors before you reach the final decision.