lengthilyadv.长地；冗长地lengthn.长度；时间长短；距离；一段；距离的测量单位length of protection保护期限Length of filter rod滤棒长度length of bolt shank栓体长度length of cantilever悬臂梁长length of root stalk初生根长度length specification长度说明length of normalline法线的长度, 法距length of the signal信号长度length of the course赛程距离length ion of length长度极限