key river basins

• 重点流域

key river basins的用法和样例：

例句

1. National standards would have stricter limits for discharge of pollutants in key river valleys.
   提高重点流域水污染物的国家排放标准。
2. Pollution control in key river valleys and regions was strengthened,and the environmental quality improved in some cities.
   重点流域和区域污染防治得到加强，部分城市环境质量有所改善。