Zhuang Guigan instructs students at the Xijin She ethnic group primary school in Shitun Town, Zhenghe County, southeast China's Fujian Province, Sept. 4, 2019. Located in mountainous region in northern Fujian, the boarding school now has 165 students. Among them, 83 students are boarders. Many students of the school are left-behind children and come from poverty-stricken families. The 62-year-old principal Zhuang Guigan, who has been engaged in education work for over 40 years, was re-employed two years ago after retirement. To take better care of left-behind children, Zhuang transformed the school into a boarding primary school in 2003. His wife Liang Chun'ai also joined the school to help take care of the children in 2004 after her retirement. Zhuang cleans the playground early every morning and patrols the campus every night. Sometimes, he has to send sick children to clinic at midnight. Zhuang has helped more than 2,000 children finish school over the past few years. (Xinhua/Jiang Kehong)