We should go to school by bus or underground rather than by car global warming.A. reducing

问题补充：

We should go to school by bus or underground rather than by car global warming.

A. reducing

B. to reduce

C. reduced

D. having reduced

答案：

A. reducing

(答案→)B. to reduce

C. reduced

D. having reduced

解析：考查非谓语动词。用不定式在句中作目的状语。句意：为了减少全球变暖，我们应该乘公交车或地铁去上学，而不是乘汽车。