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.
Most Famous Man-Made Arches: Arc de Triumph, Paris. 2. The Gateway Arch, St. Louis, United States â A 630-foot (190 m) monument in St. Louis, Missouri. Clad in stainless steel and built in the form of an arch, it is the tallest man-made monument in the United States, and the worldâs tallest arch.