A pair of polar bear cubs snuggle in an incubator at Quancheng Polar Ocean World in Qihe county, East China's Shandong province, July 19, 2015. Both the cubs are in good condition and will stay in an incubator for two months while they are artificially fed. Source: Ecns.cn

A keeper shows off a pair of polar bear cubs, one male and one female, at Quancheng Polar Ocean World in Qihe county, East China's Shandong province, July 19, 2015. Both the cubs are in good condition and will stay in an incubator for two months while they are artificially fed. Source: Ecns.cn

A keeper shows off a pair of polar bear cubs, one male and one female, at Quancheng Polar Ocean World in Qihe county, East China's Shandong province, July 19, 2015. Both the cubs are in good condition and will stay in an incubator for two months while they are artificially fed. Source: Ecns.cn

Keepers feed a pair of polar bear cubs, one male and one female, at Quancheng Polar Ocean World in Qihe county, East China's Shandong province, July 19, 2015. Both the cubs are in good condition and will stay in an incubator for two months while they are artificially fed. Source: Ecns.cn

A pair of polar bear cubs snuggle in an incubator at Quancheng Polar Ocean World in Qihe county, East China's Shandong province, July 19, 2015. Both the cubs are in good condition and will stay in an incubator for two months while they are artificially fed. Source: Ecns.cn

Keepers feed a pair of polar bear cubs, one male and one female, at Quancheng Polar Ocean World in Qihe county, East China's Shandong province, July 19, 2015. Both the cubs are in good condition and will stay in an incubator for two months while they are artificially fed. Source: Ecns.cn