The combo photo (up) shows morning scenery of Central Business District (CBD) in Beijing, capital of China, from Dec. 17 to 22, and the comparison photo (below) shows morning scenery of Beijing's CBD on Dec. 22, 2016. Beijing lifted a red alert for air pollution on Wednesday night as cold air dispersed the smog that affected the city for days. (Photo: Xinhua/Luo Xiaoguang)
