class b river造句

例句与造句

1. Monitoring of water quality at different spots along the river has shown that since the implementation of the plan, the dissolved oxygen levels ( D . O ), pH levels, turbidity, specific conductance, and E . coli levels, have all risen to meet the standards of a class B river.
2. It's difficult to find class b river in a sentence. 用class b river造句挺难的