direction of optical axis的用法和樣例：
例句
- No flat surface perpendicular to the pseudo-twofold axis could be formed.
不能自然形成垂直于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(dòng)時(shí)，我們只需涉及在該軸方向上的角動(dòng)量分量。
