gravity flow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。 - Openings in the glass facade and the ventilation shutters in the roof create a healthy natural flow and exchange of air.
開口玻璃幕牆及通風百葉窗在屋頂創造一個健康的自然流動和交換的空氣。
