问题补充：
-Excuse me.How long can I keep the book?
-You can return it by the end of this month.
A. give it away
B. come up with it
C. give it back
D. lend it again
答案：
A. give it away
B. come up with it
(答案→)C. give it back
D. lend it again
解析：return“归还”，意思同“give…back”。
