Quality tracing system introduced in E China

Wang Kai, a staff member of a cooperative, presents QR codes which are used for checking the quality of vegetables in Gaoqing County, east China's Shandong Province, Dec. 6, 2017. Quality tracing system was introduced to Gaoqing County with vegetable having its own QR code which contains basic information for customers to scan.(Xinhua/Zhu Zheng)