The greens didn`t catch the train when they got to the station the train ______________
问题描述：
The greens didn`t catch the train when they got to the station the train ______________
A.left B.was left C.has left D.had left
请说明理由
答
D had left （过去完成时）
从句when they got to the station一般过去式,主句 the train had left 发生在从句之前,所以用过去完成时.我想知道为什么不可以选was left过去完成时结构：had+动词过去分词，不会有was存在。
was left 属于 be done （被动语态）的过去式。被离开？逻辑不符合，不可这样表达。