A combination photo shows a view of the Badaling section of the Great Wall before (top and middle) and during Earth Hour on the outskirts of Beijing, March 31, 2012. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. [Photo/Agencies]

Aizhai Suspension Bridge, over the Jishou-Chadong Expressway, in Central China's Hunan province, opens to traffic on March 31, 2012. Crossing Dehang Grand Canyon, the bridge has a main span of 1,176 meters. As a key section of the expressway, the Aizhai bridge includes the standard two-way four-lane motorway, with a speed limit of 80 kilometers per hour and a base width of 24.5 meters. [Photo/CFP]