internal source of pollution的用法和樣例：
例句
- Soil erosion and non-point source pollution are two serious environmental issues.
土壤侵蝕與非點(diǎn)源污染是兩大重要的環(huán)境問(wèn)題。 - So the agricultural non-point source pollution has been considered as the main pollution source of eutrophication.
因此農業(yè)面源污染已被視為水體富營(yíng)養化的主要污染源。
