请教一个简单的英语句型结构

问题描述:

请教一个简单的英语句型结构
sorry to have kept you waiting .这句话把它拆散记忆怎么弄?keep waiting

可这样记忆:be sorry to do,抱歉做某事
keep sb doing,使某人一直做某事
keep sb waiting,使某人等了很久
祝楼主更上一层楼