The key answer of exercise 1

This 492m high building consists of two elements that correspond to the Chinese concept of the Earth as a square and the sky as a circle. The hole in the top also has a practical use - to relieve the pressure of the wind on the building. The glassy tower is being built just blocks away from the 420m Jinmao Tower in a / the district of Shanghai that has been designated the Asian centre for international banking. The tower's lower levels will be used for offices, and its upper levels for a hotel, an art museum and restaurants.