Jon Huntsman, U.S. Ambassador to China attended the opening ceremony of the U.S. pavilion for World Expo 2010 on May 1. He told China.org.cn that he started to love China since his first visit to China in 1984.

He said he witnessed the rapid urban development in Shanghai and was confident that the Expo would be a prime opportunity for Shanghai's further growth as both a financial and a cultural center.

2. China.org.cn: The US has held several Expos, and in your understanding what did these Expos bring to the US and in your understanding what are the most significant Expos held by the United States?