Panda mother Mangzai and a newly born cub are asleep at a zoo in southwest China's Chongqing Municipality, July 10, 2019. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on June 30, 2019 shows a pair of cubs born by giant panda Mangzai at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

A staff member helps giant panda Lanxiang to breastfeed a newly born cub at a zoo in southwest China's Chongqing Municipality, July 12, 2019. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Panda mother Lanxiang holds a newly born panda cub in her arms at a zoo in southwest China's Chongqing Municipality, July 6, 2019. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

A staff member helps a newly born panda cub defecate at a zoo in southwest China's Chongqing Municipality, July 10, 2019. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)

Photo taken on July 16, 2019 shows a newly born panda cub at a zoo in southwest China's Chongqing Municipality. Two giant pandas in a zoo in Chongqing gave birth to two pairs of twins on June 23. Female panda Lanxiang, 17, gave birth to a pair of male cubs in the wee hours of June 23, weighing 167 and 115 grams, respectively. Another female panda, Mangzai, gave birth to a pair of female cubs in the afternoon on the same day, measuring 142 and 160 grams in weight, respectively. (Photo: Xinhua)