RFA Wave Knight Conducting RAS Operations. Replenishment at sea (RAS) (North Atlantic Treaty Organisation/Commonwealth of Nations) or Underway replenishment (UNREP) (US Navy) is a method of transferring fuel, munitions, and stores from one ship to another while under way. 1 History 1.1 Concept.
The international non-profit organization Council on Tall Buildings and Urban Habitat (CTBUH) was formed in 1969 and announces the title of The World's Tallest Building and sets the standards by which buildings are measured. It maintains a list of the 100 tallest completed buildings in the world. The organization currently ranks Burj Khalifa in Dubai as the tallest at 828 m (2,717 ft).
The Pentagon was the world's largest office building for a while. The Vehicle Assembly Building, where NASA puts together its rockets, is pretty amazing. It was built in 1966 and was only supposed to last 10 years. It's still in use. Burj Khalifa is currently the tallest man-made structure in the world. You might find this list interesting: List of largest buildings in the world.