Cleaners do ( ).They keep our city clean and tidy A an impor

Cleaners do ( ).They keep our city clean and tidy A an impor It's a p____ way to help keep our city clean and tidy. We feel _____ our duty to keep our city clean and tidy. I think __our duty to keep our evirionment clean an tidy.A.t Everyone is s____to keep our classroom clean and tidy We should keep our classroom clean and tidy. We must keep our classroom clean and tidy句子结构 You must keep ( ) clean and tidy.a.they b.them c.their d.the street cleaners help keep our city__.a,clean b,cleaning c,to It is our duty to keep our classroom clean and tidy.中的It《our It is our duty to keep our classroom clean and tidy.中 our du I think it's our duty to keep our environment clean and tidy