A worker operates in a wheel hub for a wind power generating set at a plant of Shandong Changxing Group in Zouping County, east China's Shandong Province, March 16, 2011. The Changxing Group has mastered the technology for manufacturing wind power generating sets of a capcity from 850 kilowatts to 3,000 kilowatts, and its products, based on fully independent research and development, have been popular in Europe and the United States. [Xinhua/Dong Naide]