primitive plane

• 初基面

primitive plane的用法和样例：

例句

1. In all cases the gnomon lies in the plane of the meridian.
   表始终都处于子午面内。
2. If the wavefronts are parallel lines, the waves are called plane waves.
   假如波前为一些互相平行的轮廓面，这波就叫平面波。