friction可数么

friction这个词有好几个定义和用法，多数情况下是不可数名词，但如果用作描述人际或国际关系的摩擦和冲突，就做作可数名词用了。请看例句：

1 [uncountable] the action of one object or surface moving against another

Friction between moving parts had caused the engine to overheat.

2 [uncountable] (physics) the resistance (= the force that stops something moving) of one surface to another surface or substance moving over or through it

The force of friction slows the spacecraft down as it re-enters the earth's atmosphere.

3 [uncountable, countable]

friction (between A and B)

disagreement or a lack of friendship among people who have different opinions about something

synonym tension

conflicts and frictions that have still to be resolved