It was Carl O. Sauer who did
Answer:Ural, mountain range forming a rugged spine in west-central Russia and the major part of the traditional physiographic boundary between Europe and Asia. Extending some 1,550 miles (2,500 km) from the bend of the Ural River in the south to the low, severely eroded Pay-Khoy Ridge, which forms a 250-mile (400-km) fingerlike extension to the northern tip of the Urals proper, the mountains constitute the major portion of the Uralian orogenic belt, which stretches 2,175 miles (3,500 km) from the Aral Sea to the northernmost tip of Novaya Zemlya.
Explanation:
Overcrowding and slums developed in many impoverished countries in the 20th century, mostly due to large migrations to cities from people looking for work.
A wall stands using gravity. It is constantly being pulled down. Many also place them in ways that they dig into the ground, and almost make a socket just for the wall to be placed, using the land that is there. More and more walls are placed and eventually, they make flooring and a roof.
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