下列哪项是造成臭氧层空洞的主要原因？Which of the following is the main cause of the ozone hole?- 二氧化碳排放 Carbon dioxide emissions- 氟利昂 Chlorofluorocarbons (CFCs)- 甲烷排放 Methane emissions

下列哪项是造成臭氧层空洞的主要原因？ Which of the following is the main cause of the ozone hole? - 二氧化碳排放 Carbon dioxide emissions - 氟利昂 Chlorofluorocarbons (CFCs) - 甲烷排放 Methane emissions