原因状语从句中的虚拟语气

题目

原因状语从句中的虚拟语气
He was angry that you should call him by name.他很生气,你竟然对他直呼其名.
I was very surprised that Father should have known what I did yesterday.我很吃惊,父亲竟指导我昨天所作的事情
不懂为什么要用虚拟语气
第一句与 He was angry that you called him by name.有什么区别?难道用虚拟就表示这个不是事实了?

答案

它只是突出这种惊讶的语气,意思是竟然