Population Growth
The growth of population during the past few centuries is no proof that population will continue to grow straight upward toward infinity and doom. On the contrary, demographic history offers evidence that population growth has not been at all constant. According to paleoecologist Edward Deevey, the past million years show three momentous changes. The first, a rapid increase in population around one m illion B. C., followed the innovations of tool making and tool using. But when the new power from the use of tools has been exploited, the rate of world population growth fell and became almost stable. The next rapid jump in population started perhaps 10,000 years ago, when mankind began to keep herds, plow and plant the earth. Once again when initial productivity gains had been absorbed, the rate of population growth abated. These two episodes suggest that the third great change, the present rapid growth, which began in the West between 250 and 350 years ago, may also slow down when, or if, technology begins to yield fewer innovations. Of course, the current knowledge revolution may continue without foreseeable end. Either way - contrary to popular belief in constant geometric growth - population can be expected in the long run to adjust to productivity. And when one takes this view, population growth is seen to represent economic progress and human triumph rather than social failure.
12月大学英语四级阅读复习精选练习(1)
英语四级阅读复习必备经典习题(6)
英语四级阅读理解模拟题及解析(十五)
大学英语四级难句解析(八)
英语四级阅读理解模拟题及解析(七)
12月大学英语四级阅读复习精选练习(6)
12月大学英语四级阅读理解模拟练习(4)
大学英语四级备考:提高阅读能力的方法
12月大学英语四级阅读理解难句之定语从句
英语四级阅读理解模拟题及解析(四)
英语四级阅读理解模拟题及解析(十一)
大学英语四级阅读单选题讲解:因果条件题(4)
英语四级阅读理解模拟题及解析(八)
大学英语四级阅读单选题讲解:因果条件题(2)
英语四级阅读复习必备经典习题(9)
英语四级阅读复习必备经典习题(1)
大学英语四级阅读单选题讲解:是非题(1)
英语四级阅读复习必备经典习题(5)
12月大学英语四级阅读复习精选练习(4)
英语四级阅读理解模拟题及解析(九)
大学英语四级阅读理解精练附答案和解析(7)
英语四级阅读理解模拟题及解析(五)
名师:以真题为例 四级快速阅读解题两步走
英语四级阅读复习必备经典习题(12)
12月大学英语四级阅读复习精选练习(3)
英语四级阅读理解模拟题及解析(十二)
大学英语四级阅读长难句考前辅导(二)
英语四级阅读复习必备经典习题(7)
英语四级阅读理解模拟题及解析(十四)
2014英语四级暑假复习:要稳步提升阅读能力
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |