Teacher Jiang Qiaomu gives a lesson at Yongxing School in Sansha city on Yongxing island, the largest of the Xisha islands in South China Sea, Dec 14, 2015. Yongxing School, including a primary school, a kindergarten and a vocational education center, opened this week in Sansha, China's southernmost island city administered by Hainan Province. [Photo/Xinhua]