Father for London on business upon my arrival, so I didn’t see him.
A. has left
B. left
C. was leaving
D. had left
网友回答
A. has left
B. left
C. was leaving
(答案→)D. had left
解析：正确答案D。
难点1.leave for... 意为：出差到...
难点2. upon my arrival相当于when I arrived，是句子的状语
“父亲去伦敦出差”这一动作在“我到达”之前已经发生，故“我没见着他”。
某个动作或过程在过去的过去已经完成，与现在没有联系;而且过去完成时有一个与一般过去时动作的先后。