中考英语一模考前冲刺辅导：时间状语从句

　　连词主要有：when as while before after until as soon as since等

　　(1)区别when, as, while的用法

　　①.when"当......时候"引导的时间状语从句，其动词既可以是延续性动作的动词，也可以是瞬间性动作的动词,如：

　　_________ the students heard the teacher's footsteps, they all stopped talking.

　　当学生们听到老师的脚步声时，他们都停止了讲话。(从句动作发生在前)

　　② as"当.......时候"或"一边.......一边"引导的时间状语从句其动词的动作是延续性的，而且侧重表示主句和从句的动作并相发生：

　　We were having breakfast __________ she was combing her hair.

　　她梳头时我们在吃早饭。

　　③ while表示"在某一段时间里"或"在……期间"，其所引导的从句的动作是延续性的，并侧重表示和主句的动作同时发生。如：

　　I can learn ________ I work.

　　我可以边工作边学习。

　　用when, as, while填空：

　　________ you came in, I was talking with a few boys.

　　It started to rain __________ we were playing outdoors.

　　They talked _________ they walked down the river.