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shaft sinking

(Encyclopedia)shaft sinking, excavation from the surface of an opening in the earth. Shafts, which are generally vertical, are usually distinguished from tunnels, which are horizontal. Little difficulty is experien...

platypus

(Encyclopedia)platypus plătˈəpəs [key], semiaquatic egg-laying mammal, Ornithorhynchus anatinus, of Tasmania and E Australia. Also called duckbill, or duckbilled platypus, it belongs to the order Monotremata (s...

Hokkaido

(Encyclopedia)Hokkaido hōkīˈdō [key], island, c.30,130 sq mi (78,040 sq km), N Japan, separated from Ho...

coke

(Encyclopedia)coke, substance obtained by the destructive distillation of bituminous coal. Coke bears the same relation to coal as does charcoal to wood. A hard, gray, massive, porous fuel, coke is the solid residu...

Cascade Range

(Encyclopedia)Cascade Range, mountain chain, c.700 mi (1,130 km) long, extending S from British Columbia to N Calif., where it becomes the Sierra Nevada; it parallels the Coast Ranges, 100–150 mi (161–241 km) i...

aviation

(Encyclopedia)aviation, operation of heavier-than-air aircraft and related activities. Aviation can be conveniently divided into military aviation, air transport, and general aviation. Military aviation includes al...

mining

(Encyclopedia)mining, extraction of solid mineral resources from the earth. These resources include ores, which contain commercially valuable amounts of metals, such as iron and aluminum; precious stones, such as d...

muskrat

(Encyclopedia)muskrat, North American aquatic rodent. The common muskrats, species of the genus Ondatra, are sometimes called by their Native American name, musquash. They are found in marshes, quiet streams, and p...

diode

(Encyclopedia)diode dīˈōd [key], two-terminal electronic device that permits current flow predominantly in only one direction. Most diodes are semiconductor devices; diode electron tubes are now used only for a ...

Kabul

(Encyclopedia)Kabul käˈbo͝ol, kəbo͞olˈ [key], city (1997 est. pop. 1,500,000), capital of Afghanistan and of Kabul prov. and its largest city and economic and cultural center, E Afghanistan, on the Kabul Rive...