gravity current的用法和樣例：
例句
- The purified water then descends by gravity to a basement holding tank.
經(jīng)過(guò)凈化的水靠重力流到地下室的另一個(gè)集水箱里。 - In flat terrain, sewers enroute to a treatment a small plant may increase in depth to the point where it is impractical to continue gravity flow.
在平坦地形地帶，排水管線(xiàn)再道小型污水廠(chǎng)途中可能深度增加到以重力流不切實(shí)際。
