The world’s population is ______.

Câu hỏi :

Chances are, you are reading this article in a big city. Population growth is far faster than ever before and that is especially true in cities like Tokyo and Shanghai.

People from the countryside move to cities to find work and a better standard of living. These cities are so large they have been named megacities. The largest is Tokyo, followed by Shanghai, Jakarta, and ManilA. Some way behind is London, with a relatively small 15 million people.

However, life in cities is not always better. Homelessness is a big problem. When people do have homes, they are often in slums where disease and poor healthcare are problems.

Problems affect richer people too. Traffic blocks roads for hours in cities like Bangkok and Mexico City. Air pollution is so bad in some cities that people do not want to go out.