A planation surface of gentle relief formed through long-term denudation . The term is associated in particular with the davisian cycle of erosion
biological, physical, or chemical agent used to kill plants or animals that are harmful to people; in practice, the term pesticide is often applied
Pingos are ice-cored hills ( Figure P63 ), typically conical in shape, covered by soil and vegetation with a core of massive ice produced primarily by
large white bear , Ursus maritimus, formerly Thalarctos maritimus, of the coasts of arctic North America, Asia, and Europe. Polar bears usually live
The concept of pollution consists of the inappropriate or undesirable mixing of items or elements that may in themselves be quite appropriate or
In the last half-century, population growth has proceeded at an unprecedented rate, with the world’s population currently totaling six billion people.
Central North American plain, formerly grass-covered, extending over most of the region between the Rocky Mountains to the west, and the Great Lakes
PRECIPITATION REFERS BOTH to the process by which particles fall from clouds to the earth below, and to those particles themselves. Owing to various