mean pressure grade line

例句：

1. 1.The mean pressure gradient line is used to determine the direction of the flow.
   平均压力梯度线用于确定流体的流向。
2. 2.The mean pressure gradient line helps us understand the behavior of the fluid in the system.
   平均压力梯度线有助于我们理解系统中流体的行为。
3. 3.The mean pressure gradient line is a crucial tool for predicting the performance of the system.
   平均压力梯度线是预测系统性能的关键工具。