gravity current的用法和樣例：
例句
- The purified water then descends by gravity to a basement holding tank.
經過凈化的水靠重力流到地下室的另一個集水箱里。 - 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，排水管線再道小型污水廠途中可能深度增加到以重力流不切實際。
