A：个人及环境卫生工作
B：消灭患病动物
C：计划免疫
D：隔离有病个体
我国部分城市（地区）已禁止生产和销售含磷洗衣剂，含磷洗衣剂主要添加了三聚磷酸钠，禁止生产和销售的原因是
There are _________ ducks in the river.
— I didn't until my father came back.
