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.
Two other natural arches, Kolob Arch and Landscape Arch, both also in southern Utah, have confirmed spans several meters longer than Rainbow Bridge, but by most definitions of the terms they are considered to be arches rather than bridges.