Aerial photo taken on Dec. 15, 2019 shows constructors preparing for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province. (Photo by Xie Jianfei/Xinhua)

Constructors prepare for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province, Dec. 15, 2019. (Photo by Zhang Tao/Xinhua)

Constructors prepare for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province, Dec. 15, 2019. (Photo by Zhang Tao/Xinhua)

Constructors prepare for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province, Dec. 15, 2019. (Photo by Zhang Tao/Xinhua)

Constructors prepare for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province, Dec. 15, 2019. (Photo by Zhang Tao/Xinhua)

Constructors prepare for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province, Dec. 15, 2019. (Photo by Zhang Tao/Xinhua)

Aerial photo taken on Dec. 15, 2019 shows constructors preparing for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province. (Photo by Xie Jianfei/Xinhua)

Aerial photo taken on Dec. 15, 2019 shows constructors preparing for the opening of the Ice-Snow World in Harbin, capital of northeast China's Heilongjiang Province. (Photo by Xie Jianfei/Xinhua)