Scientist Li Zhongqin, head of Tianshan Mountains Glacier Observation Station of China Academy of Sciences (CAS), shows boots for science research at Urumqi River source Glacier No.1 in Tianshan Mountains, northwest China's Xinjiang Uygur Autonomous Region, April 29, 2017. From April 27 to 30, CAS scientists carried out a "body check" for the Urumqi River source Glacier No.1 in Tianshan Mountains including its thickness, temperature, albedo, material balance, velocity of speed, so as to analyze its changing trend over the past half century. (Xinhua/Cen Yunpeng)