题目内容
The average population density of the world is 47 persons per square mile. Continental densities range from no permanent inhabitants in Antarctica to 211 per square mile in Europe. In the western hemisphere, population densities range from about 4 per square mile in Canada to 675 per square mile in Puerto Rico. In Europe 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, in Egypt, 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 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. In timberland areas of the world, ______.
查看答案
搜索结果不匹配？点我反馈
更多问题
治疗支原体肺炎应选用（）
女性，65岁，慢性咳嗽、咳痰20余年，每年持续3个月以上，以冬季为重。近3年出现活动后气急，偶有双下肢水肿。今日晨起突感右上胸针刺样痛，继之出现呼吸困难，大汗，不能平卧，急来诊。 以下检查中最有价值的是
For Emily Dickinson there were three worlds, and she lived in all of them, making them the substance of everything that she thought and wrote. There was the world of nature, the things and the creatures that she saw, heard, felt about her, there was the "estate" that was the world of friendship. And there was the world of the unseen and unheard. From her youth she was looked upon as different. She was direct, impulsive, original, and the droll wit who said unconventional things which others thought but dared not speak, and said them incomparably well. The characteristics which made her inscrutable to those who knew her continue to bewilder and surprise, for she lived by paradoxes. Certainly the greatest paradox was the fact that the three most pervasive friendships were the most elusive. She saw the Reverend Charles Wadsworth of Philadelphia but three or four times in the course of her life, and then briefly, yet her admiration of him as an ideal and her yearning for him as a person were of us surpassed importance in her growth as a poet. She sought out for professional advice the critic and publicist Thomas Wentworth Higginson and invited his aid as mentor for more than twenty years, though she never once adopted any counsel he dared to hazard. In the last decade of her life, she came to be a warm admirer of the poet and novelist Helen Hunt Jackson, the only qualified judge among Emily Dickinson’s contemporaries who believed her to be a great poet, yet Emily Dickinson steadfastly refused to publish even though Mrs. Jackson’s importunity was insistent. According to the passage, Helen Hunt Jackson wanted ______.
[听力原文]6-8W: Good morning, Mr. Li Ming.M: Good morning, Madam.W: Be seated, please. Did you receive the application form we sent youM: Yes, I did.W: Have you brought it with youM: Yes. Here it is.W: Do you think you have the appropriate qualifications for the jobM: Yes. I’ve got a college diploma in computer science.W: Have you got any work experienceM: No. I only graduated last month. What was the man expected to bring with him（）
微信支付 
支付宝支付