2020学年高中英语 Book2 Module5 Grammar-时间状语从句和原因状语从句讲练 外研版必修2

时间状语从句和原因状语从句一、时间状语从句【语境展示】观察下面各组句子中时间状语从句的用法，并加以总结。1. a. It was raining when we left for the station.c. When the students heard the teachers footsteps, they all stopped talking.2. a. I was preparing lunch in the kitchen when the power went off.b. We were about to start when it began to rain.c. The game had hardly begun when it started raining.3. a. While the teacher explained the text in English, the students listened carefully and took notes.b. I can learn while I work.4. a. As time passed, things seemed to get worse.b. As the students walked to their classroom, they sang happily.【自我归纳】when用法小结：1. when引导时间状语从句时，表示“当的时候”，从句的动作既可与主句的动作同时发生又可在主句动作之前发生。（如第一组例句）2. when还可用于以下结构：be doing sth. when . 正在做某事时突然；be about to do sth. when . 正要做某事时突然；hardly when . 一就（如第二组例句）while用法小结：while引导时间状语从句时，表示“在期间，在某一段时间里”，从句的谓语动词常用延续性动词，侧重表示从句的动作和主句的动作同时进行。（如第三组例句）as用法小结：as引导时间状语从句时，表示“随着，一边一边”，侧重主句和从句两个动作同时发生或主句动作随从句动作的变化而变化。（如第四组例句）二、原因状语从句【语境展示】观察下面各组句子中原因状语从句的用法，并加以总结。1. a. The teacher was angry because we were late.b. Why cant I go?Because you are too young.2. a. Since travelling by air is much faster, they decided to take a plane.b. Ill do it for you since you are busy.c. Now that I am well again, I can go on with my work.d. Now that you have passed your test, you can drive on your own.3. a. As it was getting late, I turned around to start for home.b. As I didnt know the way, I asked a policeman.【自我归纳】because引导原因状语从句时，语气最强，表示直接原因，常用来回答why引出的问题。（如第一组例句）since / now that引导原因状语从句时，表示很明显的或是对方已经知晓的原因，语气较弱，译为“既然”。（如第二组例句）as引导原因状语从句时，常表示明显的原因和理由，语气较弱，比较口语化。（如第三组例句）注意：for引导的分句不表示直接的原因，而是用来附带解释说明前面一句的情况。for引导的分句常位于句子后部，与前一分句以逗号隔开。如：Fred felt no fear, for he was brave.【即学即练】I. 选用when, while, as并用其正确形式填空。1. They were singing _ we were dancing.2. Alice was walking cross the street _ he met his brother.3. _ the time went on, the weather got worse.II. 用because, now that, for并用其正确形式填空。1. The game was called off _ it rained.2. _ youve passed your test you can drive on your own.3. I belie