She went to London after she【had passed 】the exam.
在她通过考试之后,她就去了伦敦.
考察：过去完成时.When I ran to the platform quickly, the train (?)(leave).had left已经离开了。说明在你到达站台之前就已经离开了。或者填 was leaving 说明 火车正在离开。但是个人倾向于过去完成时