Without facts, we cannot form a worthwhile opinion for we need to have factual knowledge ______ our thinking.
A.which to be based onB.which to based onC.on which to baseD.to which to be based在线课程C
句意为“没有事实，我们不能形成一个有真正价值的意见，因为我们需要有确凿的知识作为我们思考的依据”。该句是...knowledge on which we should base our thinking.的省略形式。