问题补充：
The moment I got home, I found Imy jacket on the playground.
A. had left
B. left
C. have left
D. was leaving
答案：
A. had left
B. left
C. have left
D. was leaving
解析：主句动词为过去式，从句动作又早于主句动作，即过去的过去，应用过去完成式。
备考：过去完成时，即过去的过去。如：
When I got to the station, the train had left.
By the time he was twelve, Edison had began to make a living by himself.
She said (that) she had never been to Paris.
