【正确答案】After millennia of slow growth that was hardly noticed by each generation, cities are suddenly and rapidly reaching out in every direction. Urban population in China increases by 7 percent a year, while in big cities the rate may be as high as 10 percent a year. To give only one visible example of accelerated urban expansion, Shanghai now grows by 10 buildings and 100 square metres of road every hour. Besides, there is no reason to believe that this pace will slacken in recent years. With rural areas gradually shrinking, we are now heading towards an urbanized society as the vast majority of rural people move into cities.