—How can I the books?—Three weeks.A. long; borrowB. often; borrowC. long; keep D. often;

问题补充：

—How can I the books?

—Three weeks.

A. long; borrow

B. often; borrow

C. long; keep

D. often; borrow

答案：

A. long; borrow

B. often; borrow

(答案→)C. long; keep

D. often; borrow

解析：how long多长；how often多久一次；borrow借入；keep保持，持有。根据下文，三周。可知上文问的是，这本书我能拿多久？borrow是瞬间动词，不能和表示一段时间的时间状语连用，故选C。