【单选题】I was about to leave _____ the telephone rang.
【单选题】排烟机旁的排烟防火阀,常开,火灾时,280°C关闭( )。
【单选题】Yesterday I was about to leave for the market _____ my boss called and asked me to go back to the office at once.
【单选题】I was about to leave _____ the telephone rang.
【单选题】从新民主主义过渡到社会主义,是我国近现代历史一个重要发展阶段,这一过渡时期特指____。
【单选题】样本 取自总体 , , ,则以下结论不成立的是