A bicycle, also called a cycle or bike, is a human-powered or motor-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A bicycle rider is called a cyclist, or bicyclist.[from wikipedia]

Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds.[from wikipedia]

The United Nations (UN) is an intergovernmental organization that was tasked to maintain international peace and security, develop friendly relations among nations, achieve international co-operation and be a center for harmonizing the actions of nations. The headquarters of the UN is in Manhattan, New York City, and is subject to extraterritoriality. Further main offices are situated in Geneva, Nairobi, and Vienna.[from wikipedia]