用连续运动、不断变化的观点确定曲面体表面的点线

Guiding Your Listening and Speaking Class

用高等数学中几何学的理论和物理学中的连续运动和不断变化的观点探讨画法几何学中曲面体的表面特性．从构成几何体的表面元素和不断变化的过程来讨论这些曲面体，把传统的画法几何学中对曲面体的描述进一步动态化。

English teachers have long been discussing what role a teacher should play in class.A teacher can act different roles at different times,but,in my opinion,he or she is more like a captain of a ship,setting the sailing course,and letting the sailors (students) do the rest of the job.