Seals are seen at an interactive area at the Harbin Polarland in Harbin, capital of northeast China's Heilongjiang Province, July 21, 2016. Six newly-arrived seals made their public debut in Harbin on Thursday. (Xinhua/Wang Kai)

Seals are seen at an interactive area at the Harbin Polarland in Harbin, capital of northeast China's Heilongjiang Province, July 21, 2016. Six newly-arrived seals made their public debut in Harbin on Thursday. (Xinhua/Wang Kai)

Seals are seen at an interactive area at the Harbin Polarland in Harbin, capital of northeast China's Heilongjiang Province, July 21, 2016. Six newly-arrived seals made their public debut in Harbin on Thursday. (Xinhua/Wang Kai)

Seals are seen at an interactive area at the Harbin Polarland in Harbin, capital of northeast China's Heilongjiang Province, July 21, 2016. Six newly-arrived seals made their public debut in Harbin on Thursday. (Xinhua/Wang Kai)