Our earth is getting warmer and warmer. It is time for us to the emission(排放) of CO2.A. b

问题补充：

Our earth is getting warmer and warmer. It is time for us to the emission(排放) of CO2.

A. break down

B. cut in

C. cut down

D. cut off

答案：

A. break down

B. cut in

(答案→)C. cut down

D. cut off

解析：考查短语辨析。A. break down抛锚；B. cut in插嘴；C. cut down消减；D. cut off切断。句意：我们的地球变得越来越暖，是该我们消减二氧化碳排放的时候了。故C正确。