Li Mingsong, a sanitation systems maintainer at Qiqihar North Depot — China's northernmost passenger train depot . He & 39 colleagues ensure hygienic travel across 138 conventional trains & 256 onboard restrooms. (Photo by Yang Lei / China Youth Daily)

By Wang Xinyuan,Li Yuanyuan and Sun Jiamin(intern)/China Youth Daily

Source：China Youth Daily

来源：中国青年报客户端