衍生　present adj. 出席的，到场的；现在的，目前的；存在的，含有的
翻译　The children showed unusual constraint in the presence of the new teacher（在新教师面前显得很拘束）.
同义替换　①attendance; existence
principal [?pr?ns?pl] adj. 最重要的，主要的 n. ①负责人，校长 ②资本，本金
拆分　prin（主要的，第一）+ cip（拿，抓，握住）+ al（人物）→第一个拿主意的人→校长
例句　The employee posted abroad who speaks the country’s principal language has an opportunity to fast-forward certain negotiations, and can have the cultural insight to know when it is better to move more slowly.