New York, London, Paris and many other cities are exciting places to live. There are lots of interesting things to see and do.But there arc serious problems in big cities too. It is expensive to live there, and there are too many people. Every year many people move to the cities to find work, saidy at good schools and receive high-quality medical care, but sometimes these people can’t find work or good places to live. Also it is hard to keep big cities safe and clean.So, before people move to a big city, they should think about these problems they might have to deal with there.