Complex sentence: The tallest skyscraper in Shanghai is the Shanghai World Financial Center, which is tall with 101 floors, and is the tallest building in the People's Republic of China and currently the third-tallest in the world.
Split into simpler sentences: The tallest skyscraper in Shanghai is the Shanghai World Financial Center, which is tall with 101 floors. It is currently the tallest building in the People's Republic of China and the third-tallest in the world.