Have you finished the book＿＿＿you borrowed from the library?A. which B. it C. what

问题补充：

Have you finished the book＿＿＿you borrowed from the library?

A. which B. it C. what

答案：

解析：关系代词用法。句意：你已读完了你从图书馆里借的那本书了吗？根据句意可知，这是一个定语从句，先行词book为物，it不能作关系词，这里需要一个作定语的关系代词，故用which而不用what。