I must return the two books to the library. I them for 20 days.A. borrowedB. keptC. have

问题补充：

I must return the two books to the library. I them for 20 days.

A. borrowed

B. kept

C. have kept

D. have borrowed

答案：

A. borrowed

B. kept

(答案→)C. have kept

D. have borrowed

解析：根据上一句内容I must return the two books to the library，故选答案为C