—You seem to have known Dr. Ken for a long time.—That’s truehe joined our club years ag

问题补充：

—You seem to have known Dr. Ken for a long time.

—That’s true. he joined our club years ago.

A. Since

B. Until

C. When

D. If

答案：

(答案→)A. Since

B. Until

C. When

D. If

解析：连词辨析。A. 自从……以来 B.直到 C. 既然，当……时D. 是否，如果。句意：你好像认识肯博士很久了。——是的，自从他几年前加入我们俱乐部以来。故选A。