Students of Qingdao No.1 Middle School play on a playground built on the roof of a commercial building in the downtown area of Qingdao, East China`s Shandong Province, March 24, 2004. [Xinhua] Students of Qingdao No.1 Middle School play on a playground built on the roof of a commercial building in the downtown area of Qingdao, East China`s Shandong Province, March 24, 2004. [Xinhua]