Staff members make preparation at the check-in counters in the terminal 1 of Nanjing Lukou International Airport in Nanjing, east China's Jiangsu Province, July 29, 2020. The terminal 1 of the airport was put into operation Wednesday after renovation. And the annual passenger capacity of the airport's two terminals reaches 50 million. (Xinhua/Ji Chunpeng)

A child looks at robots in the terminal 1 of Nanjing Lukou International Airport in Nanjing, east China's Jiangsu Province, July 29, 2020. The terminal 1 of the airport was put into operation Wednesday after renovation. And the annual passenger capacity of the airport's two terminals reaches 50 million. (Xinhua/Ji Chunpeng)

Photo taken on July 29, 2020 shows the exterior of the terminal 1 of Nanjing Lukou International Airport in Nanjing, east China's Jiangsu Province. The terminal 1 of the airport was put into operation Wednesday after renovation. And the annual passenger capacity of the airport's two terminals reaches 50 million. (Xinhua/Ji Chunpeng)

A staff member tests the equipment at the self-service baggage check-in counter in the terminal 1 of Nanjing Lukou International Airport in Nanjing, east China's Jiangsu Province, July 29, 2020. The terminal 1 of the airport was put into operation Wednesday after renovation. And the annual passenger capacity of the airport's two terminals reaches 50 million. (Xinhua/Ji Chunpeng)

People walk to the terminal 1 of Nanjing Lukou International Airport in Nanjing, east China's Jiangsu Province, July 29, 2020. The terminal 1 of the airport was put into operation Wednesday after renovation. And the annual passenger capacity of the airport's two terminals reaches 50 million. (Xinhua/Ji Chunpeng)