Jiang Xiulan explains as her students study in a class in Qingxi Central Primary School in Chaerlong village, Wushi town, Huangshan City of east China's Anhui Province, Sept. 7, 2018. Since 1983 when she began her career as a teacher, Jiang has been working in the "one teacher in one school" model in which all the subjects of all the students in the school is taught by a single teacher. Jiang is now giving a curriculum of seven courses in the school where a total of five students study in two grades. (Xinhua/Wang Zhengzhong)