液压阻力的英文：
flowed friction

flowed是什么意思：
v. 流动；源自，来自
n. 流；流动；流畅；连贯；大量

Exercise stimulates the flow of blood.
锻炼促进血液循环。

free flowing contour
自然起伏的地形

The flow of fluid is steady.
液体的流动很稳定。

A flow of words is no proof of wisdom
口若悬河不能作为才智的证明。

Flowing with milk and honey
鱼米之乡

friction是什么意思：
n. 摩擦；摩擦力；不和，争执

family friction
家庭的不和

These two countries have political friction.
这两国政治上失和。

The rougher the surface, the greater the friction.
物体表面越粗糙，产生的摩擦力越大。

We must distinguish sliding friction from rolling friction
我们必须把滑动摩擦同滚动摩擦区别开来。

political friction between two countries
两国间政治上的不和