Aerial photo taken on Aug. 27, 2019 shows Wu Guoxian and students attending a flag-raising ceremony at Gugang Primary School in Liuguang Village of Longli County in Bouyei-Miao Autonomous Prefecture of Qiannan, southwest China's Guizhou Province. Located deep in the mountains, Gugang Primary School in Liuguang Village welcomed six preschool students and four first-graders when the new semester began on Monday. They will be taught by Wu Guoxian, the only school teacher here. Wu, 53, has been working at the school for 36 years since he graduated from a junior high school in 1983. The school had a decrepit teaching building and scarce teaching facilities when Wu started working here. So he made blackboards and desks on his own for students. Apart from teaching-required courses, Wu assumed other roles at the school, including cook and cleaner. Over the decades, Wu has not only taught about 800 students, but also witnessed the enormous changes that happened to the school, from a one-classroom shell to a two-layer concrete building. In addition to teaching students in first and second grades subjects like Chinese, math, music, PE and science, Wu also provides free preschool education for children in the village, in an effort to help students walk out of the mountain and explore the world partly by what they have learnt here. "Even if there is one student left, I will still stay at my post," said Wu. (Xinhua/Yang Wenbin)