Chinese basketball player Yao Ming, the official face of the 2010 Shanghai World Expo, gives a speech during an event to promote environmental protection for the 2010 Shanghai World Expo in Shanghai, February 10, 2010. (Xinhua/Fan Jun)

 

Chinese basketball player Yao Ming, the official face of the 2010 Shanghai World Expo, gives a speech during an event to promote environmental protection for the 2010 Shanghai World Expo in Shanghai, February 10, 2010. (Xinhua/Fan Jun)

 

China's 110m hurdle athlete Liu Xiang signs in an event to promote environmental protection for the 2010 Shanghai World Expo in Shanghai, February 10, 2010. (Xinhua/Fan Jun)

 

China's 110m hurdle athlete Liu Xiang (L) poses for a photo with a boy during an event to promote environmental protection for the 2010 Shanghai World Expo in Shanghai, February 10, 2010. (Xinhua/Fan Jun)