问题
单项选择题
—Did Alan enjoy seeing his old friends yesterday
—Yes, he did. He（）his old friends for a long time.
A. didn't see
B. wouldn't see
C. hasn't seen
D. hadn't seen
答案
参考答案：D
解析：
题干表达的意思为“他已经很长时间没见过他的老朋友了”，时态为过去完成时。故选D。