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The average population density of the world is 47 persons per square mile. Continental den
High population densities generally occur in regions of developed industrialization, such as the Netherlands, Belgium, and Great Britain, or where lands are intensively used for agriculture, as in Puerto Rico and Java.
Low average population densities are characteristic of most underdeveloped countries. Low density of population is generally associated with a relatively low percentage of cultivated land. This generally results from poor-quality lands. It may also be due to natural obstacles to cultivation, such as deserts, mountains or malaria-infested jungles, to land uses other than cultivation, as pasture and forested land, to primitive methods that limit cultivation, to social obstacles, and to land ownership systems which keep land out of production.
More economically advanced countries of low population density have, as a rule, large proportions of their populations living in urban areas. Their rural population densities are usually very low. Poorer developed countries of correspondingly low general population density, on the other hand, often have a concentration of rural population living on arable land, which is as great as the rural concentration found in the most densely populated industrial countries.
Along the banks of the Nile, we may expect to find ______.
A.1,300 persons
B.few inhabitants
C.pyramids
D.many settlements
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