Visitors view a marsh gas generator during the China International Energy Saving, Emission Reduction and New Energy Science and Technology Expo at the Beijing Exhibition Center in Beijing, capital of China, on March 22, 2009. [Xinhua]

Visitors views an ecological farm house model featuring earthquake resistance and energy saving during the China International Energy Saving, Emission Reduction and New Energy Science and Technology Expo at the Beijing Exhibition Center in Beijing, capital of China, on March 22, 2009.  [Xinhua]