Without facts,we can not form a worthwhile opinion,for we ne

Without facts,we can not form a worthwhile opinion,for we need to have factual knowledge ____...
Without facts,we can not form a worthwhile opinion,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 wo be based
which to do 是个什么句式 A中的which to be done 是表示被动?分析下句子成分 ,如果A的on提前可以吗