Without facts we can’t form a correct opinion for we need to have actual knowledge our thi

问题补充：

Without facts,we can’t form a correct opinion,for we need to have actual knowledge our thinking.

A. which to be based on

B. on which to base

C. which to base on

D. which to base

答案：

A. which to be based on

(答案→)B. on which to base

C. which to base on

D. which to base

解析：本题考查“疑问词+不定式”的用法。把句子的后半部分补全为：for we need to have actual knowledge on which we base our thinking。 base… on…把…建立……基础上。