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.
15 photos: Natural bridges around the world. Hazarchishma Natural Bridge, Afghanistan â Wildlife Conservation Society researchers traveling to Afghanistan to conduct a wildlife survey stumbled upon Hazarchishma Natural Bridge, perhaps one of the largest in the world.