Jack doesn’t smoke now but he for almost twenty years.A. was smokingB. had smokedC. has

问题补充：

Jack doesn’t smoke now, but he for almost twenty years.

A. was smoking

B. had smoked

C. has smoked

D. smoked

答案：

A. was smoking

B. had smoked

C. has smoked

(答案→)D. smoked

解析：考查时态，由后面的时间状语for almost twenty years，可以知道是一般过去式，句子意思“杰克现在不吸烟了，但是他吸烟将近”