I’m not sure whether this is the book my brother read the year before last.A. whoseB. asC

问题补充：

I’m not sure whether this is the book my brother read the year before last.

A. whose

B. as

C. what

D. which

答案：

A. whose

B. as

C. what

(答案→)D. which

解析：本题中修饰名词book为定语从句，先行词表示物，故关系词使用which，故本题选D。