Enlisted personnel are identified by way of their various 'E' grades ranging from E-1 to E-9. For those service branches recognizing a Warrant Officer rank, 'W' grades range from W-1 to W-5. Likewise Officers are scaled from O-1 to O-10.
China has quite a collection of natural bridges, including one that experts say has the longest span of any natural bridge in the world. The Fairy Bridge (Xianren Qiao), in southwestern China's Guangxi Zhuang Autonomous Region near the border with Vietnam, has a 400-foot span.
Development of this List. In October 2010 a NABS group confirmed that Fairy Bridge in China has the greatest span in the world. For many years the only two known contenders for this position were Landscape Arch in Arches National Park and Kolob Arch in Zion National Park.