unit 1：一：1：know ledge 2：educational 3：programme 4：excitement 5：polluted二：BADCDADBCB三：1：they have to turned the open space into a pretty garden 。2：they have to worked here since 1998.3：she is felling a bit tired。4：we used to swim in that river。5：in the past，we have no phone tv set。四：DBDACABADC五：1：piaying
