(220417) -- WASHINGTON, D.C., April 17, 2022 (Xinhua) -- Giant panda cub "Xiao Qi Ji" (R) and its mother "Mei Xiang" enjoy an ice cake at Smithsonian's National Zoo in Washington, D.C., the United States, April 16, 2022. Various events were held to mark the 50th anniversary of the giant panda program of the Smithsonian's National Zoo and Conservation Biology Institute on Saturday. In 1972, then-Chinese Premier Zhou Enlai gifted two giant pandas to the United States as a gesture of goodwill following then-U.S. President Richard Nixon's groundbreaking visit. Then-Zoo Director Theodore Reed personally escorted the bears from China, and they arrived in Washington, D.C., on April 16, 1972. (Xinhua/Liu Jie)