A man takes part in a flash mob with a child at Shanghai Hongqiao Railway Station in east China's Shanghai, Sept. 17, 2019. Participants chorused patriotic songs during the flash mob as a way to celebrate the 70th anniversary of the founding of the People's Republic of China. (Photo: Xinhua)

Passengers and staff members of Shanghai Hongqiao Railway Station take part in a flash mob in east China's Shanghai, Sept. 17, 2019. Participants chorused patriotic songs during the flash mob as a way to celebrate the 70th anniversary of the founding of the People's Republic of China. (Photo: Xinhua)

Passengers and staff members of Shanghai Hongqiao Railway Station take part in a flash mob in east China's Shanghai, Sept. 17, 2019. Participants chorused patriotic songs during the flash mob as a way to celebrate the 70th anniversary of the founding of the People's Republic of China. (Photo: Xinhua)

Passengers and staff members of Shanghai Hongqiao Railway Station take part in a flash mob in east China's Shanghai, Sept. 17, 2019. Participants chorused patriotic songs during the flash mob as a way to celebrate the 70th anniversary of the founding of the People's Republic of China. (Photo: Xinhua)

Staff members of Shanghai Hongqiao Railway Station take part in a flash mob in east China's Shanghai, Sept. 17, 2019. Participants chorused patriotic songs during the flash mob as a way to celebrate the 70th anniversary of the founding of the People's Republic of China. (Photo: Xinhua)