Passengers wait for boarding at Terminal 2 of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province, Aug. 4, 2020. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)

Staff members load goods onto a passenger plane at the apron of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province, Aug. 4, 2020. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)

A passenger plane is seen on the apron of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province, Aug. 4, 2020. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)

Passengers wait for boarding at Terminal 2 of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province, Aug. 4, 2020. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)

A passenger plane is seen on the apron of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province, Aug. 4, 2020. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)

Photo taken on Aug. 4, 2020 shows Terminal 2 of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)

Passengers prepare to board a plane at Terminal 2 of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province, Aug. 4, 2020. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)

A passenger plane is seen on the apron of the extended Zhangjiakou Ningyuan Airport in Zhangjiakou, north China's Hebei Province, Aug. 4, 2020. The extended Zhangjiakou Ningyuan Airport, one of the key supporting infrastructure developments for the 2022 Beijing Winter Olympics, was completed and put into service on Monday. The expansion project includes a new terminal, an emergency rescue center, an apron, and an extended runway, among others. (Photo by Wu Diansen/Xinhua)