How long may I this book? For about a week.A. borrowB. borrowedC. keepD. kept

问题补充：

How long may I this book? For about a week.

A. borrow

B. borrowed

C. keep

D. kept

答案：

A. borrow

B. borrowed

(答案→)C. keep

D. kept

解析：how long 与延续性动词连用，而四个选项中，只有CD为延续性动词，同时在may引导的疑问句中，动词要用动词原形，故选C