这句话前半句怎么解释?The first exhibitors conference of China Shanghai

这句话前半句怎么解释?
The first exhibitors conference of China Shanghai World Expo 2010 opened here on Wednesday with organizers saying they would provide developed nations and international organizations with more than 500 patches,each with an area of 500 sq m,to design and build exhibition booths according to their needs
请问,在saying 前面的话怎么能解释的更通顺些,