Aerial photo taken on Jan. 14, 2021 shows the construction site of a centralized medical observation center in Shijiazhuang, capital of north China's Hebei Province.Photo:Xinhua

Photo taken on Jan. 14, 2021 shows a scene of the construction project to build a center for centralized medical isolation in Shijiazhuang City, capital of north China's Hebei Province.Photo:Xinhua

Photo taken on Jan. 14, 2021 shows a scene of the construction project to build a center for centralized medical isolation in Shijiazhuang City, capital of north China's Hebei Province.Photo:Xinhua

Photo taken on Jan. 14, 2021 shows a scene of the construction project to build a center for centralized medical isolation in Shijiazhuang City, capital of north China's Hebei Province.Photo:Xinhua

Aerial photo taken on Jan. 14, 2021 shows the construction site of a centralized medical observation center in Shijiazhuang, capital of north China's Hebei Province.Photo:Xinhua

Workers put up prefabs on the construction site of a centralized medical observation center in Shijiazhuang, capital of north China's Hebei Province, Jan. 14, 2021.Photo:Xinhua