secondary bus辅助总线secondaryadj.次要的；从属的；中等教育的n.副手；次要位置secondary plant再加工技术设备secondary metal再生金属secondary curve二次曲线secondary range次等草场secondary light次要光secondary spore次生孢子Secondary apnea继发窒息secondary amide仲酰胺secondary stock次级股票secondary shoot次生茎