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.
6. Natural Bridge-Caverns at Natural Bridge are the deepest caverns on the East Coast and go 34 stories underground below the earth's surface to see nature's magnificent underground landscape of dripstone, flowstone, draperies, pools, stalactites, and stalagmites.