bath-tub curve

例句：

1. 1.The bath-tub curve is a crucial factor in determining the shape of the water surface.
   浴缸曲线是决定水面形状的关键因素。
2. 2.The bath-tub curve was used to predict the flow of water during a flood.
   浴缸曲线被用来预测洪水期间水流的情况。
3. 3.The bath-tub curve was studied to improve the design of swimming pools.
   研究浴缸曲线是为了改进游泳池的设计。