Staff members of Chongqing Zoo hold two pairs of newborn giant panda twins in their arms at an outdoor naming ceremony 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)