【题目】As soon as I got to the airport, I realized I ________ my ID card at home.
A. had leftB. has left
C. would leaveD. will leave
在线课程【答案】A
【解析】
试题分析：考查时态。句意：一到机场，我就意识到我将身份证忘在家里了。根据语境可知，leave my ID card at home是发生在realized之前，用过去完成时。故选A。
【知识归纳】
过去完成时态表示过去的过去。When I got there, the train had left.当我到达那里的时候，火车已经离开。