Photo taken on May 16, 2019 shows giant panda Xiao Liwu at the Qingchengshan Base of the China Conservation and Research Center for Giant Pandas in Dujiangyan, southwest China's Sichuan Province. Two giant pandas have returned to China after staying in the United States for years. Twenty-seven-year-old female giant panda Bai Yun and its son, six-year-old Xiao Liwu, arrived in Sichuan Province on Thursday, after the San Diego Zoo's conservation loan agreement with China ended. (Xinhua/Xue Yubin)