Passengers allowed to use QR codes to enter Shenzhen Metro stations

A volunteer of Shenzhen Metro shows a smartphone-generated QR code that serves as an electronic ticket in Shenzhen, south China's Guangdong Province, May 8, 2018. Passengers are allowed to use QR codes as electronic tickets to enter all stations of Shenzhen Metro starting from Tuesday. (Xinhua/Mao Siqian)??