Visitors look at two penguins from Harbin Polarland at an indoor ski arena of a snow resort in Harbin, northeast China's Heilongjiang Province, April 6, 2019. (Xinhua/Wang Jianwei)

Visitors look at two penguins from Harbin Polarland at an indoor ski arena of a snow resort in Harbin, northeast China's Heilongjiang Province, April 6, 2019. (Xinhua/Wang Jianwei)

Visitors look at two penguins from Harbin Polarland at an indoor ski arena of a snow resort in Harbin, northeast China's Heilongjiang Province, April 6, 2019. (Xinhua/Wang Jianwei)

Visitors look at a penguin from Harbin Polarland at an indoor ski arena of a snow resort in Harbin, northeast China's Heilongjiang Province, April 6, 2019. (Xinhua/Wang Jianwei)

Visitors look at two penguins from Harbin Polarland at an indoor ski arena of a snow resort in Harbin, northeast China's Heilongjiang Province, April 6, 2019. (Xinhua/Wang Jianwei)