Since cities have changed a lot, thesize of the cities has grown enormously. Discuss thecauses and consequence ofthe enormous size of cities. Nowadays, the maps of cities areupdated frequently. With the development of city, moreand more suburbs becomeparts of the city. When the cities in the world are amplifying constantly,people discuss the topic hotly, the causes and consequence of the enormouscities.Different people have different answers by their respective views.

　　In my opinion, the evolution of societyand the development of economy result in thegrowth of the vast size of cities.Since the number of population in every city is increasingcontinually, peopleneed a large amount of space to live in. With the progress of the technology,the output of crops rises sharply. Fewer and fewer farmers are required, as aresult,more and more villages urbanize. The growth of the cities brings usmany huge changes.There are more job opportunities inthe cities. For instance, China will hold the Olympic Games in Beijing in 2008.The government is amplifying the size of Beijing to build new gyms inorder tohold it excellently. Obviously, people in the cities could gain a lot of newjobs.

　　Of course, the enormous size of citiesalso has bad effects. Pollution is becoming more andmore serious all over theworld with the amplification of the cities. For example, the poisonousgas sentoff by factories and automobiles has made the air unhealthy for people tobreathe.Water waste keeps pouring into rivers and lakes; as a result, manywater species are dying out.Furthermore, more people the city have, morerubbish we can find.

　　In a word, since each coin has twosides, we should be acquainted clearly with the reasonswhy the size of thecities has grown enormously and what it will bring us. Thus, we could makefulluse of the positive effects and overcome the negative effects.