首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Populations tend to grow at an exponential (指数的) rate. This means that they progressively double. As an example of this type of
Populations tend to grow at an exponential (指数的) rate. This means that they progressively double. As an example of this type of
admin
2012-07-17
57
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.
It took______for the world to increase its population from 1 billion to 4 billion.
选项
A、100 years
B、149 years
C、19 years
D、over two million years
答案
B
解析
本题是一道根据具体细节推算类问题。问需要多长时问世界人口从10亿增加到了40亿。文章第二段指出,从有人类生活开始到1830年,地球上的人口达到10亿,这代表着至少200万年的一个时期。从1830年到1930年世界人口达到20亿;到1960年又增加了10亿人口,这仅有30年的时间;1979年世界人口达到40亿,这样,在15年期间又增加了10亿人。因此,本题的正确答案应是B:1979—1830=149年。
转载请注明原文地址:https://kaotiyun.com/show/fEXO777K
0
在职攻硕英语联考
相关试题推荐
I’venever______thetheorythatpeoplearemoreimportantthananimals.
IntheUnitedStatesandinmanyothercountriesaroundtheworld,therearefourmainwaysforpeopletobe【C1】______aboutdeve
IntheUnitedStatesandinmanyothercountriesaroundtheworld,therearefourmainwaysforpeopletobe【C1】______aboutdeve
IntheUnitedStatesandinmanyothercountriesaroundtheworld,therearefourmainwaysforpeopletobe【C1】______aboutdeve
IntheUnitedStatesandinmanyothercountriesaroundtheworld,therearefourmainwaysforpeopletobe【C1】______aboutdeve
TheJapanesedesireformarriagehadbeenverystrong.Inthefifth""worldyouthattitudesurvey""【C1】______bytheManagementa
TheJapanesedesireformarriagehadbeenverystrong.Inthefifth""worldyouthattitudesurvey""【C1】______bytheManagementa
Ayearhas______andthereisnosignofthesituationgettinganybetter.
Cultureisactivityofthought,andreceptivenesstobeautyandhumanefeeling.【C1】______ofinformationhavenothingtodowith
随机试题
船舶载运危险货物申报时须递交《船舶载运危险货物申报单》,填写的内容主要有()。
首次公开发行股票的信息披露方式主要包括:发行人及其主承销商应当将发行过程中披露的信息刊登在至少两种中国证监会指定的报刊,同时将其刊登在中国证监会指定的互联网网站,并置备于中国证监会指定的场所,供公众查阅。( )
(2017年)根据企业破产法律制度的规定,下列免于申报的破产债权是()。
教学中依次要完成的九大教学事项有哪些?
成就动机理论的主要代表人物是()。
对未完成义务教育的未成年犯和被采取强制性教育措施的未成年人应当进行义务教育,所需经费由()予以保障。
简述是否动机越强学习效果越佳?
最近的一项研究指出:“适量饮酒对妇女的心脏有益。”研究人员对1000名女护士进行调查,发现那些每星期饮酒3~15次的人,其患心脏病的可能性较每星期饮酒少于3次的人低。因此,研究人员发现了饮酒量与妇女心脏病之间的联系。以下哪项如果为真,最不可能削弱上述论证?
曹锟贿选
Somepeoplebelievethatyouhavetobeaspecialkindofpersontosellaproduct.Butalthoughitisclearthatasuccessfuls
最新回复
(
0
)