USA Pavilion

USA Pavilion

Qilai Shen/Bloomberg

Long lines of visitors wait outside the USA Pavilion after its official opening to the public at the 2010 World Expo Site in Shanghai, China, on Monday, May 3, 2010. Shanghai's $44 billion World Expo opened its gates to the public two days ago as China's richest city prepares to host an estimated 70 million visitors during the six-month long event.