In Permafrost Regions,the Topmost Portion of Ground That Undergoes Thawing

question 4

Multiple Choice

In permafrost regions,the topmost portion of ground that undergoes thawing and freezing is the

• A) transition zone.
• B) thermokarst.
• C) discontinuous layer.
• D) frost zone.
• E) active layer.

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Definitions:

Convention Of 1818

An agreement between the U.S. and Britain that settled the Canada-U.S. border along the 49th parallel for much of its stretch and allowed joint occupancy and settlement of the Oregon Territory.

Great Lakes

A group of five large freshwater lakes in North America that include Lake Superior, Michigan, Huron, Erie, and Ontario, collectively forming the largest group of freshwater lakes in the world by total area.

Joint Occupation

A situation where two or more parties share control and governance of a certain territory or area, often as a result of a treaty or mutual agreement.

Erie Canal

A man-made waterway completed in 1825 that connected the Great Lakes with the Atlantic Ocean through the Hudson River, significantly impacting trade and settlement in the United States.