2. 职称英语
  3. Populations tend to grow at an exponential (指数的) rate. This means that they

Populations tend to grow at an exponential (指数的) rate. This means that they

游客2025-03-18  21
问题     Populations tend to grow at an exponential (指数的) rate. This means that they progressively double. As an example of this type of growth rate, take one penny and double it every day for one month. After the first week you would have only 64 cents, but after the fourth week you would have over million dollars.
    This helps explain why the population has come on "all of a sudden". It took from the beginning of human life to the year 1830 for the population of the earth to reach one billion. That represents a time span of at least two million years. Then it took from 1830 to 1930 for world population to reach 2 billion. The next billion was added by 1960, only thirty years, and in 1979 world population reached 4 billion, which is another billion people in only fifteen years.
    World population is increasing at a rate of 9 000 per hour, 220 000 per day, 80 million per year. This is not only due to high birth rates, but to lower death rates as well. The number of births has not declined at the same rate as the number of deaths.
    Some countries, such as Colombia, Thailand, Morocco, Costa Rica, and the Philippines, are doubling their populations about every twenty-one years, with a growth rate of 3. 3 percent a year or more. The United States is doubling its population about every eighty-seven years, with a rate of 0. 8 percent per year. Every time a population doubles, the country involved needs twice as much of everything, including hospitals, schools, resources, food and medicines to care for its people, it is easy to see that this is very difficult to achieve for the more rapidly growing countries. [br] Which of the following statements is NOT true?
选项 A、World population is increasing at a rate of 150 per minute.
B、Lower death rate also contributes to world population growth.
C、The population of Colombia has been doubling every year for 21 years.
D、The United States is usually doubling its population about every 87 years.
答案 C
解析 本题是一道判断是非类问题。问下面哪个说法是不正确的。针对四个选项，利用查阅式阅读法并结合原文相关内容，我们可以推断出本题的正确答案应是C“哥伦比亚的人口已经每年持续翻番达21年”。这种说法与文章最后一段的第一句话内容不符。这句话指出，在诸如哥伦比亚、泰国、摩洛哥、哥斯达黎加及菲律宾等国家，每隔21年人口便增加一倍，每年的增长率达3．3％或者更高。
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