Children visit polar aquarium in the Hongqiao District Experimental Primary School in north China's Tianjin Municipality, July 8, 2013. The Hongqiao District Experimental Primary School Polar Aquarium, the first of its kind in Tianjin, opened on Monday. (Xinhua/Liu Dongyue)

Children visit polar aquarium in the Hongqiao District Experimental Primary School in north China's Tianjin Municipality, July 8, 2013. The Hongqiao District Experimental Primary School Polar Aquarium, the first of its kind in Tianjin, opened on Monday. (Xinhua/Liu Dongyue)