Ⅰ.阅读理解(共15小题；每小题2分，满分30分)
A
Many of the world's countries have reached or are approaching Zero Population Growth (ZPG)．Nearly all such lands are economically well developed.They include much of Europe(including Russia), the United States, Canada, Japan and Australia.As the Rate of Natural Increase(RNI)declines, two things happen.First, the population begins to decline if the loss is not balanced by immigration.Second, a country's population ages because there are fewer births.
