参考答案

正确答案：B
解析：推理判断题。要求根据文中第三段判断引起全球变暖的原因。Among factors that may be contributing to global warming are the burning of coal and petroleum products... and use of fossil fuels.可知B未提及，因此正确。methane n.甲烷、沼气；nitrous oxide n.一氧化二氮；ozone n.臭氧；deforestation n.森林开伐