Aerial photo taken on Dec. 29, 2018 shows Beijing Daxing International Airport under construction in Beijing, capital of China. The construction of the main terminal's exterior walls has wrapped up at that time. June 30 marks the end of the new airport infrastructure construction and the start of the preparatory stage of the airport's operation. The new airport is scheduled to be put into operation before Sept. 30. (Xinhua/Ju Huanzong)