A Chinese girl wears a mask at Jingshan Park during the haze day in Beijing, China, 19 December 2016. Serious air pollution hit in China's nine provinces and cities, with haze hanging over an area of about 1.42 million square kilometers on 18 December. The air pollution alert lasts in many part of China that the heavy pollution is expected to persist over 11 provinces and cities on 19 December 2016. (Photo by Wu Hong/EPA)
