Zhou Hongjun rings a bell to begin a class in Dayou primary school in Xinhe village, Rongshui Miao Autonomous County, south China's Guangxi Zhuang Autonomous Region, May 28, 2019. Zhou Hongjun, a teacher of 46 years' experience, works in a school since he was 16 in the remote rural area in Rongshui Miao Autonomous County. Before 2010, there wasn't road access to the school, all school supplies were taken by Zhou himself with a carrying pole. Zhu, supposed to retire in 2018, decided to continue his career as there was no substitute teacher to take his place. (Xinhua/Lu Boan)