n.（河流）上游源头...

For controlling source pollution from the sources, sloping land management in the headwater regions is necessary.为了从源头上控制农业面源污染,必须根据土壤生物热力学原理,以土壤为中心, 大力治理坡地.In arid climates, surface water is generally better than water ...

headwater的音标：headwater的英式发音音标为：['hedwɔ:tə(r)]headwater的美式发音音标为：['hedwɔtə(r)]...