A team member checks a yak's hoof injury during a border patrol in northwest China's Xinjiang Uygur Autonomous Region, Dec. 25, 2020. A division of Xinjiang Production and Construction Corps in Yecheng County of Tumxuk is stationed in the hinterland of the Kunlun Mountains at an average altitude of about 4,000 meters. A team in the Corps regularly heads towards the mountain peaks and patrols the border with yaks. (Xinhua/Hu Huhu)