Photo taken on Sept. 12, 2012 shows the sand table which simulated a thermal power plant during the 3rd Sino-Arabian Energy and Chemical Engineering Expo in Yinchuan City, northwest China's Ningxia Hui Autonomous Region. Over 800 enterprises from above 30 countries and regions participated in the five-day expo which kicked off on Wednesday. The expo is part of the 3rd China-Arab States Economic and Trade Forum. (Xinhua/Peng Zhaozhi)