英语问题AS的用法

题目

英语问题AS的用法
In no time ,everyone was doubled up .tears streaming from eyes.their shoulders rising and faling as wave after wave of laughter swept the crowd .
wave after wave of laughter 此句与their shoulders rising and faling
连接时为何要用AS,此句中AS 到底为何意.为何要这样用请详解.谢谢 啦

答案

此处的as引导的伴随状语,“随着”
【译文】人们立刻都笑弯了腰,随着一浪一浪的笑声传过人群,眼泪流出了,人们的肩膀起起伏伏.