英语翻译At no time in history has there been such a mass movemen

英语翻译At no time in history has there been such a mass movement of people from the countryside to the city as is happening now．By the year 2030,it’s imated that more than two thirds of the world’s population will be living in cities,twice as many as today．This means that the problems faced by cities today——overcrowding,poor housing,unemployment,poverty and lack of food and water——will be twice as bad,unless we find sol-utions soon．Another serious issue is how to provide good tran-sportation for their citizens．Many of the world’s major cities are already struggling with out-of-date transp-ortation structures．How can they deal with the addi-tional demands?London is a good example．Its enlargement was made possible by the invention of the steam engine,which powered the world’s first underground railway．But its transport systems are now hopelessly out—of-date and need urgent modernization．London’s future success depends very much on developing better public transport．Over a million people travel into central London every day from outside the city．They,and the people who live in London,want a public transport system that is efficient,safe and environmentally friendly．What they often get,however,falls far short of that ideal．Commut-ers complain about cost and pollution,while businesses worry,about the problems their staff have in getting to work on time．Yet,the proportion of London households that own a car grew from just over 10 percent in the early 1950s to over 60 percent today.As the city has become increasingly crowded and polluted,there has been a growing realization that ac-tion must be taken soon．