Task: Text Categorization
Input (English): This city features a skyscraper with two L-shaped pillars joined at the top, the CCTV Headquarters. This city monitors its air quality with a five-grade system, the best two of which are reported as ""blue sky days"". Other recent construction in this city includes twelve of its fourteen subway lines and a stadium known as the (*) ""bird's nest"", while older structures here include the Temple of Heaven and the Meridian Gate. For 10 points, name this metropolis which is home to Tiananmen Square and Forbidden City, capital of the People's Republic of China.
Output (English): Social Science