Section Ⅱ Grammar——状语从句课前自主预习[例句·体验]1．It was snowing when we got to the airport.我们到达机场时，天正下着雪。2．He had put the broken vase away before his mother came back.他趁妈妈还没回来就把打碎的花瓶收拾好了。3．He has written to me frequently since I got sick.自从我病了以后，他经常给我写信。4．Not until recently did I know what he had done.直到最近我才知道他所做的事。5．You will improve your oral English if you keep on practising.如果你坚持练习的话，你将会提高你的英语口语。6．Don't go out tomorrow morning in case Mr Li should come to visit you.明天上午不要出去以防李先生会来拜访你。7．However difficult (No matter how difficult) the work is，we will try our best to finish it in time.无论工作多么困难，我们都要尽全力及时完成。8．Young as/though he is, he knows a lot about life.尽管他很小，但他对生活懂得挺多。课堂合作探究[语法·讲座] 一、时间状语从句 引导时间状语从句的连词有 when, while, as, after, before, since, until, till, as soon as, once, the moment, the minute, immediately, every time, next time 等。1．when 引导的时间状语从句。(1)when 引导时间状语从句时，表示“当……的时候”，从句中谓语既可用延续性动词也可用非延续性动词。1(2)在以下句式中 when 表示“这时(突然)”：be about to do sth./be on the point of doing sth.when ... (正要做某事这时……)；be doing sth.when ... (正在做某事这时……)；had done sth.when ... (刚做完某事这时……)。(3)when 还用于 hardly ... when ... (一……就……)中，这时，when 从句中常用一般过去时，主句用过去完成时。当 hardly 位于句首时，主句用部分倒装，通常把助动词 had 放在主语的前面。①When I came home my mother was cooking dinner. 我回家时，妈妈在做晚饭。(短暂性动词)②When I lived in the countryside, I used to carry some water for him. 当我住在农村时，我常常为他送水。(延续性动词)③We were about to leave when he came in.我们正要离开，就在那时他进来了...
