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.
China's Great Wall is the world's longest architectural structure and is widely renowned as one of the seven great wonders of the world. The wall stretches 6,700 kilometers (4,163 miles) from the Jiayuguan Pass in Gansu Province to the Shanhaiguan Pass in Hebei Province.