Question

there are so manymake up my mind to buy

There are so many kinds of reference books on sale that I can't make up my mind which ________．（　　）

A. to be bought

B. to buy

C. buying

D. bought

Answer 1

答案：B．
本题中，应该是用"which+不定式"的结构来在句中做宾语，故排除C、D；在"疑问词+动词不定式"的省略结构中，动词（buy）的逻辑主语应该就是主句的主语I，它们之间构成主动关系，故应用主动形式"to buy"，选B．