MONGOLIA/

Chimney stacks from a power station billow smoke on a grassy plain located on the outskirts of the Mongolian capital city of Ulan Bator April 6, 2012. Mongolia is expected to be one of the world's fastest-growing economies over the next decade as a result of a mining boom and billions of dollars in foreign investment. REUTERS/David Gray (MONGOLIA - Tags: ENERGY BUSINESS)