There are altogether eleven books on the shelf, ________ five are mine.

A.on which

B.in which

C.of which

D.from which

答案及解析： C

解析：

思路

分析：本题考查定语从句的用法。要选择正确的介词，首先应确定定语从句的先行词是eleven books，再看它和定语从句的关系是five of eleven books are mine，of which five=five of which，表示“其中的5本”。句意：“书架上有十一本书，其中五本是我的。”