英语单选15the principal purpose of aviation medicine is _____ by people aboard an aircraft in flighta,to study the stress experiencedb,study the experienced stressc,to study stress experiencingd,study the stress experience

英语单选15the principal purpose of aviation medicine is _____ by people aboard an aircraft in flighta,to study the stress experiencedb,study the experienced stressc,to study stress experiencingd,study the stress experience THE PRINCIPAL怎么样 关于principal与the principal的问题Who is ________ of your school?A. principal B. the principal C. a principal D. an principal答案是B 我选A了 principal不是校长的意思吗?职务前不是不加定冠词the的 What is the Pareto Principal? the outstanding principal amount是什么意思 talking to the principal是什么意思 英语冠词语法题by the time he was 38,he had become principal of a university.其中,为什么principal 前面没有冠词? 第15,英语单选 英语单选10-15 “The Principal Shipping Officer”中文是什么? Principal in the head____ a school.(填空) The secretary and principal怎么翻译? embrace the universal principal是啥意思 talking to the principal音标 和意思 哪位朋友帮帮忙做下英语题~~急需答案~!谢谢了题号:16 题型:单选题（请在以下几个选项中选择唯一正确答案） 本题分数:5内容:The principal ______ a diploma to each of the graduates.选项: a、presented b 华东理工大学英语网上作业求高手,好的加分题号:11 题型:单选题（请在以下几个选项中选择唯一正确答案） 本题分数:5内容:The principal dwelled ______ traffic safety in his talk.选项:a、onb、inc、atd、 怎样区分the,a,/英语单选常常出现的! My uncle is（ ）principal of the NO.2 High School of Wuxi.A /B the选哪个?为什么?