principal act主要行为principaladj.主要的；首要的n.本金；资本；校长；主角；委托人；主犯Principal value of the estate遗产的基本价值Principal conmponent analysis主成分分析principal projection property主射影性质Principal Assistant Secretary主任助理秘书principal components anslysis主成分分析principal vertical deflection主要高低提前量Principal Contracting Officer首席合同签订军官principal residential address主要住址Principal part of advertising广告主体principal in the first degree第一主犯； 首犯； 一级主犯