Engineers work at an underground generator of the Three Gorges Project, the No 32 turbine in Yichang, Central China's Hubei province, April 26, 2011. The turbine launched a water-filling test on Tuesday, starting the debugging of this unit. If the test goes well as planned, the turbine will be operating starting in May. Three of all six underground generators at the Three Gorges will be operational by this summer. [Photo/Xinhua]