540. in progress(=in the state of be done)进行中

539. proceed with ( =begin and continue sth.) 继续进行

538. proceed from (=arise from, result from) 由…发出, 由…引起(产生)

537. in private (=privately) 私下, 秘密地 in public 公开地

536. prior to (=before) 在…之前

535. in principle (=only in regard to the main idea) 原则上

534. pride oneself on / upon 以…自豪

533. take pride in(=pride oneself on) 以…自豪

532. previous to (=prior to) 在…之前

531. prevent…from 使…不, 防止…做