polar line and plane

• 极线和极面

polar line and plane的用法和样例：

例句

1. Pollen grain trilobate in polar view.
   花粉粒三裂在极面观。
2. The angles refer to the polar view angle, i.e. the angle measured from the vertical.
   角涉及到极面观的角，例如垂直物上测量的角。