The Sandhills region of Nebraska is a paradise for nature lovers. Covering one quarter of the state, it consists of dunes, some reaching 300 feet high, along with grasslands, and shallow lakes. A driving tour through the Sandhills, often described as one of the most scenic in the USA, is a great way to explore the area.
opponent(Noun) An individual or group who is a rival of another. opponent(Noun) One who attempts to stop the progression of. opponent(Noun) One who objects to. opponent(Noun) In team sports, a player of an opposite team.
Opponent-Process Theory. the theory that opposing retinal process (red-green, yellow-blue, white-black) enable color vision. eg: some cells are stimulated by green and inhibited by red; some are stimulated by red and inhibited by green.