A staff worker checks the No. 27 turbine at the Three Gorges' underground power station in Yichang, central China's Hubei Province, May 23, 2012. The No. 27 turbine, the last 700,000-kilowatt turbine generator of the Three Gorges' power station, finished a 72-hour trial operation successfully Wednesday afternoon. [Xinhua]

A staff worker walks past the No. 27 turbine at the Three Gorges' underground power station in Yichang, central China's Hubei Province, May 23, 2012. The No. 27 turbine, the last 700,000-kilowatt turbine generator of the Three Gorges' power station, finished a 72-hour trial operation successfully Wednesday afternoon. [Xinhua]

A staff worker walks past the No. 27 turbine at the Three Gorges' underground power station in Yichang, central China's Hubei Province, May 23, 2012. The No. 27 turbine, the last 700,000-kilowatt turbine generator of the Three Gorges' power station, finished a 72-hour trial operation successfully Wednesday afternoon. [Xinhua]

A staff worker checks the No. 27 turbine at the Three Gorges' underground power station in Yichang, central China's Hubei Province, May 23, 2012. The No. 27 turbine, the last 700,000-kilowatt turbine generator of the Three Gorges' power station, finished a 72-hour trial operation successfully Wednesday afternoon. [Xinhua]

Photo taken on May 23, 2012 shows the interior scene of the Three Gorges' underground power station in Yichang, central China's Hubei Province. The No. 27 turbine, the last 700,000-kilowatt turbine generator of the Three Gorges' power station, finished a 72-hour trial operation successfully Wednesday afternoon. [Xinhua]