1：The river is very dirty,I think there will be more( pollution).
2:I live in an (apartment).
3:When you get on the bus,you must(stand)(in)(line)(排队）and wait for your turn.
4:He took off his coat and (left) it at the door.
5:I was (reviewing )my lessons at home this time yesterday.
6:“Thank you very much.”“Don't( mention) it .”