I never forget the days when I enjoyed a good time in Beijing.A. have B. to haveC. hadD.

问题补充：

I never forget the days when I enjoyed a good time in Beijing.

A. have

B. to have

C. had

D. having

答案：

A. have

B. to have

C. had

(答案→)D. having

解析：enjoy后面一般接动名词作宾语，表示享受，喜欢做某事。故选D。