secondary air二次风secondaryadj.次要的；从属的；中等教育的n.副手；次要位置secondary circle次大圆,副圈secondary fossil次生化石secondary fibril次级细丝secondary modernn.现代中学secondary-loan次贷secondary tissue次生组织secondary villus次级绒毛secondary moment副力矩,次要力矩,二阶矩,二次矩secondary system二次系统； 辅助系统secondary ageing二次时效