Zuogong County is located in southeastern Tibet, China. It covers three towns, seven villages, and 127 administrative villages. The whole county has only one middle school, Zuogong County Middle School. Su Xin is the headmaster of Zuogong County Middle School, he is from Liangshan, Sichuan Province. His wife, Gan Runmei is also from Sichuan, and is now an English teacher at the school. They both went to Tibet for teaching after graduating from university in 2001. In 18 years, the school has changed a lot.