underground flow的用法和樣例：
例句
- Where underground water comes to the surface, there are oases.
地下水流到地表的地方，就成為了綠洲。 - The development of subsurface flow in soil slope due to rainfall infiltration has been studied with numerical analysis.
摘要對降雨滲入坡面土壤所產(chǎn)生地下水流的進(jìn)展過(guò)程進(jìn)行了數值解析計算。
