They are sitting around tables,chatting,drinking tea or reading a newspaper.为什么可以这么表达啊?

题目

They are sitting around tables,chatting,drinking tea or reading a newspaper.为什么可以这么表达啊?

答案

chatting,drinking tea or reading a newspaper这是伴随状语,表示和主句谓语动词 are sitting 同时发生.并且其动作执行者也是主句的主语They