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 components method主成分分析principal part of discourse话语主体principal isobaric surfaces标准等压面principal componentanalysis主成分分析principal mode of vibration主振动形式principal-mode excitation主模激励Principal - agent relation委托代理关系principal polarization plane主极化面principal vestibular nucleus前庭内侧核principal supplying interest主要供货利益