I’m sorry to keep you for almost two hours.A. waitB. to waitC. waitingD. waited

问题补充：

I’m sorry to keep you for almost two hours.

A. wait

B. to wait

C. waiting

D. waited

答案：

A. wait

B. to wait

(答案→)C. waiting

D. waited

解析：使某人不断的做某事通常可写成keep sb doing sth，故选C。