rapidsn.急流；湍流rapidadj.短时间发生的；急速的；迅速的；快的；险峻的n.急流；湍滩rapid steel tool高速钢工具rapidogen orange快速精橙rapid onset rate快增长率rapid-erection快速起竖rapid repository快速长效药Rapid technology快繁Rapid Test Strep甲型链球菌快速鉴定试剂rapid simulation快速仿真rapid feathering快速冷却rapid heart beat心跳过快

1. He focuses the lens of a microscope.
   他调整显微镜的透镜以定焦点。
2. A lens is an optical system including two refracting surfaces.
   一个透镜是包含两个折射面的光学系统。