gravity flow的用法和样例：
例句
- The purified water then descends by gravity to a basement holding tank.
经过净化的水靠重力流到地下室的另一个集水箱里。 - 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.
在平坦地形地带，排水管线再道小型污水厂途中可能深度增加到以重力流不切实际。 - Openings in the glass facade and the ventilation shutters in the roof create a healthy natural flow and exchange of air.
开口玻璃幕墙及通风百叶窗在屋顶创造一个健康的自然流动和交换的空气。
