Hou Changliang volunteered to teach at Xiangyang Primary School in a remote village in Yunnan province in August 2017. There was just one problem. The local government wanted to close the school due to inadequate teacher supply.

There were just three temporary teachers for about 100 students across four classes. Shutting down the school meant that the students would have to go to another school far from their homes. Hou's arrival helped keep the school open.

It is the third village school that Hou, 34, has taught at since he graduated from Hunan University of Arts and Science in Changde, Hunan province, in 2011. Before Xiangyang Primary School, he had taught in Hechi, Guangxi Zhuang autonomous region, for four years, and in Bijie, Guizhou province, for two years.

"The longer I stayed in the countryside, the deeper I understood the challenge in rural education. Rural schools need teachers, especially good ones," Hou says, adding that a good teacher can make a real difference in a student's life and can even change a village.

As a volunteer teacher, he receives a monthly allowance of about 800 yuan ($124). This has remained unchanged for the past 10 years.