词汇	building head
释义	building head n.成型机机箱
随便看	principal right of labor principal rights principal risk principal river principal road principal role principal root principal rotating motion principal route principal rules principals principal saddle principals at basic educational sector principal scale principal screw principal screw theory principal search direction Principal Sea Transport Officer principal secondary focal length principal secretary principal section principal section of a quadric principal section of crystal principal section of quadric principal section plane