Giant panda Ya Ya carries newly born cubs in her arms at Qinling Panda Breeding Research Center in northwest China's Shaanxi Province, Aug. 2, 2021. (Photo/Shen Jiena)

A staff worker assists Ya Ya with breastfeeding at Qinling Panda Breeding Research Center in northwest China's Shaanxi Province, Aug. 2, 2021. (Photo/Shen Jiena)

A staff worker conducts physical examination for giant panda cubs at Qinling Panda Breeding Research Center in northwest China's Shaanxi Province, Aug. 2, 2021. (Photo/Shen Jiena)

Giant panda Ya Ya carries newly born cubs in her arms at Qinling Panda Breeding Research Center in northwest China's Shaanxi Province, Aug. 2, 2021. (Photo/Shen Jiena)

Giant panda Ya Ya carries newly born cubs in her arms at Qinling Panda Breeding Research Center in northwest China's Shaanxi Province, Aug. 2, 2021. (Photo/Shen Jiena)

Giant panda Ya Ya carries newly born cubs in her arms at Qinling Panda Breeding Research Center in northwest China's Shaanxi Province, Aug. 2, 2021. (Photo/Shen Jiena)