归纳as 用法，精讲精练，突出高考考点

as 引导从句的用法
（一） as作为从属连词，可以引导下列从句：
1．时间状语从句，意为“正当。。。的时候”、“一面...一面”、“随着”，从句可放之前或之后。
1),As I was coming here， I met your brother。
2),As he walked on，he felt himself getting more and more tired。
2, 原因从句，“由于”大多位于主句之前，偶尔在前或后。
3),As this question is of great importance， we will discuss it once again。
4),Water，as it occurs in natrue， is never very pure.
5),We couldn‘t send the children to school as life was very hard in those days 。
3, 方式状语从句， “如同”、“按照。。。。的方式、样子、办法”。As从句总跟在主句之后。
6). You must try to hold the tool as I do 。象我那样拿住工具。
7),Leave things as they are。让那些东西保持原样。