必修四UNITS 35,1.until.“直到时候”；not.until.“直到才”The meeting was put off until ten oclock.会议推迟到十点钟。,Not until all the fish died in the river did the villagers realize how serious the pollution was.(倒装句)等到湖里的鱼全死光了，村民们才意识到污染是多么严重。,2unless.“除非，如果不”(if.not)I wont attend his birthday party unless invited(unless I am invited)除非被邀请，否则我不会去参加他的生日晚会。,3主语be doing.when.“正在做某事这时”I was walking along the river when I heard a drowning boy cry for help.我正在河边散步，这时我突然听到一个落水男孩求救。,4主语be about to do.when./主语be on the point of(doing).when.“刚要这时”I was about to leave when it began to rain.我刚要离开，这时下雨了。,5主语had done.when.“刚做完这时”I had just finished my exam paper when the bell rang，announcing the class was over.我刚做完作业，下课铃响了。,本部分内容讲解结束,按ESC键退出全屏播放,