Without facts,we cannot form a worthwhile opinion,for we need to have factual knowledge ______ our thinking.

A.upon which to base                                       B.which to be based on

C.which to base on                                           D.to which to be based on

Without facts, we cannot form a worthwhile opinion, for we need to have factual knowledge _____ our thinking.

A. upon which to base                          B. which to be based on

C. which to base on                             D. to which to be based on

Without facts, we cannot form a worthwhile opinion, for we need to have factual knowledge _____ our thinking.

A. upon which to base 　　　　　　　 B. which to be based on

C. which to base on　　　　　　　　 D. to which to be based on

Without facts, we cannot form a worthwhile opinion for we need to have factual knowledge ______ our thinking.

1. A.
   which to be based on
2. B.
   which to based on
3. C.
   on which to base
4. D.
   to which to be based

Without facts, we cannot form a worthwhile opinion, for we need to have factual knowledge ______ our thinking.

A. which to base on　　　　 　　　 B. which to be based on

C. to which to be based on　 　　　　 D. upon which to base