had happened when信息详情
发生在什么时候
had happened───已经发生过（happen的过去完成时）
happened───vi.发生（happen的过去式及过去分词）
happened to───碰巧
had───aux.已经（用于过去完成时和过去完成进行时）；v.有；吃；得到（动词have的过去式和过去分词）
happened next───接下来发生的事
happened by───发生在
no happened───没有发生过
What happened───发生了什么事；发生了什么；白宫内幕
had ever had───曾经有过
Finally, the avoidant baby acted as if nothing had happened when the mother left and returned to the room.───最后，对于“回避型”婴儿，当妈妈离开房间，再返回时，他的表现是好像什么事情都没有发生。
What people were like when they came in had greater consequence than what happened once they were there.───人们来的时候是什么样子比他们来的时候发生了什么更重要。
When I told her what had happened she just grunted and turned back to her book.───我告诉她出了什么事，她只哼了一声就又看起书来了。
Both men had hardly had time to realize what had happened when they were thrown violently into the sea.───那个人未来得及弄明白所发生的事，突然都被猛烈地抛进了大海。
Sometimes in the past I had got into trouble, and that had happened when I followed my impulse and blasted discretion away.───过去我有时候遇到麻烦，就因为凭冲动办事，把谨慎抛到了脑后。
I even told Mun what had happened when we were about to leave the house in Tianjin to start to Beijing;───我甚至告诉妈妈就在我们即将离开天津动身去北京时所发生的事；
But something had happened when she'd touched on the subject of Tony.