People attend an outdoor naming ceremony for two pairs of newborn giant panda twins at Chongqing Zoo in southwest China's Chongqing Municipality, Sept. 30, 2019. The two pairs of giant panda twins, born on the same day by their mothers Lanxiang and Mangzai on June 23, were named Shuangshuang, Chongchong, Xixi and Qingqing respectively at Monday's ceremony. (Xinhua/Tang Yi)