motion: n.1.运动,动,移动(opp. rest)。2.(天体的)运行；(车、船等的)动摇；(机器的)开动,运转；【机械工程】机械装置,机制。3.动作,举动；手势；眼色；姿态；〔pl.〕(个人或团体的)行动,举动,活动。4.(议会中的)提议,动议；动机,意向；刺激；【法律】申请,请求。5.大便；〔pl.〕排泄物。6.【音乐】(旋律、曲调的)变移。短语和例子M- itself is
One involves not sound waves but ripples on the surface of a liquid or along the interface between layers of superfluid helium , which is so cold that it has lost all frictional resistance to motion 其中一种牵涉到的并非声波，而是液体表面或是沿著两层超流氦之间介面传播的涟漪（超流氦冷到在运动时完全没有摩擦阻力） 。
