The skirts on sale are all beautiful. I can’t decide which one .A. buyB. to buyC. bought D

问题补充：

The skirts on sale are all beautiful. I can’t decide which one .

A. buy

B. to buy

C. bought

D. will buy

答案：

A. buy

(答案→)B. to buy

C. bought

D. will buy

解析：句意：正在减价销售的裙子都很漂亮。我不能决定买哪一件。动词不定式做定语表示具体的将要发生的动作，疑问词+不定式可以起相当于宾语从句的作用。如果选D，则从句缺少主语，故选B。