【题目】Although we produce carbon when we breathe, the carbon we produce is much less than________ produced by a car.
A. It B. one which
C. the one D. that
在线课程【答案】D
【解析】
考查替代。句意：虽然我们在呼吸时产生碳，但我们生产的碳比汽车所产生的碳要少得多。“the+不可数名词”用that替代，此处用that替代the carbon，故选D。