After having been wounded towards the end of the war,he had been sent to hospital and was separated from his unit.
问题描述：
After having been wounded towards the end of the war,he had been sent to hospital and was separated from his unit.
have been wounded 完成时,
he had been sent 过去完成时,
was separated 一般过去时,
这三个时态用法是为什么,第一个为什么用完成时,而不有过完成时?
答
having been wounded 表示持续动作,到战争结束时伤都没好,当主从句的主语一致时,从句的主语可以省略,同时原来的have改成having.had been sent是相对于was separated来说的,sent的动作在separated之前发生,所以它用过去完成时,表示过去的过去