No flat surface perpendicular to the pseudo-twofold axis could be formed. 不能自然形成垂直於偽二次軸方向的平坦的表面小平面。
In deducing the motion we will need to concern ourselves only with the component of angular momentum related to this axis. 在分析這種運動時,我們只需涉及在該軸方向上的角動量分量。