The OC/EC ratio in nighttime ranging from 2.4 to 2.7 is higher than that in daytime ranging from 1.9 to 2.0. The organic pollution level and OC/EC ratio in Beijing is higher than other observation results in Japan and USA.是什么意思_The OC/EC ratio in nighttime ranging from 2.4 to 2.7 is higher than that in daytime ranging from 1.9 to 2.0. The organic pollution level and OC/EC ratio in Beijing is higher than other observation results in Japan and USA.在线翻译_英语_读音_用法_例句