off adv.表示状态的关闭或离开prep.离开；在...之外adj.空闲的；离开的；关闭的v.离开；脱下
双语例句
The ray propagating and paraxial imaging characteristics of a GRIN fiber lens with constant refractive-index surfaces of revolution paraboloids are studied. 本文研究一种等折射率面为旋转抛物面的梯度折射率纤维的光线传播和近轴成像特性。
