English for more than six years, he can speak and work very well with that businessman from England.
A. To have learned
B. To learn
C. Learning
D. Having learned
网友回答
A. To have learned
B. To learn
C. Learning
(答案→)D. Having learned
解析：考查非谓语动词。learn和speak，work有先后关系，应该用完成时，learn的逻辑主语是he，是主谓关系，故用主动形式。故选D。