Workers set up a power transmission tower at an alternating and direct current construction site in the Golmud suburb of Qinghai province on March 30, 2011. Nearly 10,000 workers joined the project, dubbed "the power sky road" on Qinghai-Tibet Plateau because it was constructed at an average altitude of 4,500 meters, with a direct investment of 16.2 billion yuan ($2.4 billion). It will be a project at the highest altitude of its kind in freezing conditions, with a total length of 1,038 kilometers after its year-end completion. The project enables the power system in Tibet to connect with the national power system. [Photo/Xinhua]