Question

15．往往是火灾发生时，人们才意识到了解消防知识的重要性．
Usually people don't realizethe importance of knowing some knowledge about fire fighting until fires happen．

Answer 1

分析 the importance of knowing some knowledge about fire fighting until fires happen．

解答 答案：the importance of knowing some knowledge about fire fighting until fires happen．这里是说客观事实用一般现在时，realize是动词意识到，是一个及物动词，后直接加上宾语，这里是加上名词短语做宾语，…的重要性用of所有格the importance of，后接名词代词或动名词，了解know，一些消防知识some knowledge about fire fighting，故the importance of knowing some knowledge about fire fighting，后用until直到引导的时间状语从句，主语泛指fires火灾，发生happen（偶然发生），故答案是the importance of knowing some knowledge about fire fighting until fires happen．

点评 until表示动作、状态的持续，强调"一直到…为止"，或强调某个动作或状态一直持续到另一个动作或状态出现之前．常与表示延续性动作的动词连用．
如：*I waited until three o'clock，but he didn't come．*He lived with his parents until he graduated from college．