---How long may I the book?-For two weeks. A. borrowB. lendC. keepD. buy

问题补充：

---How long may I the book?

---For two weeks.

A. borrow

B. lend

C. keep

D. buy

答案：

A. borrow

B. lend

(答案→)C. keep

D. buy

解析：句意：这本书我可以借多久？两周。Borrow借入；lend借出；buy买；keep保持。How long是对一段时间的提问，句中动词该是延续性动词，所以选C，其他三个都是非延续性动词。