题目内容：

without facts ,we can not form a worthwhile opinion,
接上for we need to have factual knowledge ——our thinking
A which to be based on
B upon which to base
C which to base upon
D to which to be based

优质解答

选B,without facts ,we can not form a worthwhile opinion,for we need to have factual knowledge upon which to baseour thinking.后半句的正常语序为：for we need to baseour thinking upon （on）factual know...