请问principal clinical investigator如何翻译?

请问principal clinical investigator如何翻译? principal barrier如何翻译 英国NICE National Institute of Clinical Excellence如何翻译 翻译principal what is the company's principal field of activity如何翻译 请问Principal components analysis是什么东西啊? 请问经济学中的principal agent problem是什么意思 请问principal和principle的区别 The secretary and principal怎么翻译? clinical progression 请问 请问英语如何翻译! 请问hysteresis如何翻译?