They may get up when they know they are expected to stay seated and may create a disturbance by running around inappropriately.

当他们知道自己可能要一直坐的是时候，他们会站起来，还可能到处不恰当地乱跑进行捣乱。

The main cause to create harmonic error are the relative vibration in system, in stability of geometry configuration, random disturbance and in sufficient feeding ability of the machine tool.

谐波误差产生的主要原因是系统相对振动、几何布局失稳、随机干扰和机床进给能力不足。