考博考试

【单选题】The average population density of the world is 47 persons per square mile.Continental densities range from no permanent inhabitants inAntarctica to 211 per square mile inEurope. In the western hemisphere, population densities range from about 4 per square mile inCanada to 675 per square mile in Puerto Rico. InEurope the range is from 4 per square mile in Iceland to 831 per square mile in the Netherlands. within countries there are wide variations of population densities. For example, inEgypt, the average is 55 persons per square mile, but 1,300 persons inhabit each square mile in settled portions where the land is arable.
High population densities generally occur in regions of developed industrialization, such as the Netherlands,Belgium, and GreatBritain, or where lands are intensively used for agriculture, as in Puerto Rico and Jav
A、
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.
The title below that best expresses the main idea of this passage is ______.
A、How People Live
B．PopulationDistribution
C．Economics and Population
D．PopulationDensities

网考网参考答案：D
网考网解析：
表达本文大意的最佳标题是：人口密度(Population Densities)。本文作者谈到世界上一些国家的人口密度。讲到自然环境对人口密度的影响以及经济环境对人口密度的影响，所以选D最合适。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>