A staff member holds a giant panda to feed it a birthday cake at the Chongqing Zoo in southwest China's Chongqing Municipality June 23, 2020. The Chongqing Zoo held a birthday party for four one-year-old giant pandas named Shuangshuang, Chongchong, Xixi, Qingqing respectively. (Xinhua/Tang Yi)

A staff member takes care of giant pandas at the Chongqing Zoo in southwest China's Chongqing Municipality June 23, 2020. The Chongqing Zoo held a birthday party for four one-year-old giant pandas named Shuangshuang, Chongchong, Xixi, Qingqing respectively. (Xinhua/Tang Yi)

Four giant pandas enjoy food during their birthday party at the Chongqing Zoo in southwest China's Chongqing Municipality June 23, 2020. The Chongqing Zoo held a birthday party for four one-year-old giant pandas named Shuangshuang, Chongchong, Xixi, Qingqing respectively. (Xinhua/Tang Yi)

Visitors make a birthday cake for giant pandas at the Chongqing Zoo in southwest China's Chongqing Municipality June 23, 2020. The Chongqing Zoo held a birthday party for four one-year-old giant pandas named Shuangshuang, Chongchong, Xixi, Qingqing respectively. (Xinhua/Tang Yi)