thousands of Chinese students，Chuck has vast experience in the Chinese class.
A. Having taught
B. Taught
C. Teaching
D. To have taught
网友回答
(答案→)A. Having taught
B. Taught
C. Teaching
D. To have taught
解析：考查非谓语动词作状语。Chuck与teach之间是主动关系，并且前面粉刺的动作发生在谓语动词之前，故用现在分词的完成时，句意：查克教了成千上万的中国学生之后，在中国的课堂上他有丰富的经验。所以选A。