Land, usually flat, upon which grass
predominates. The plains cover large areas of
the Earth's surface, especially between the
deserts of the tropics and the rainforests of
the equator, and have rain in one season
only. In such regions the climate belts move
north and south during the year, bringing
rainforest conditions at one time and desert
conditions at another. Examples include the
North European Plain, the High Plains of the
USA and Canada, and the Russian Plain also
known as the steppe.