As we all know, Beijing, Shanghai, Shenzhen, Hangzhou, and other big cities are great places to live . There are always something (interest)for people to see and do. You can go to, different kinds of museums, see all kinds of plays and concerts. You can also buy things all over the world,

    But there  (be)serious problems in big cities, too. For example, It's very expensive  (live)there, and there are too many people in big cities-Every student can study at good schools and receive good medical care. sometimes people can't find work or good flats with proper price. Also it is hard to keep the cities (safety)and clean.

    Some people enjoy (work) in big cities,(other) do not they want to move to a big city, they should think about the problems of living there first.