New York, London, Paris and other big cities are exciting places to live in. There are man

y interesting things to see and do. You can go to different kinds of museums, plays and films. You can also buy things from all over the world.

But there are serious problems in big cities too. It's expensive to live there, and there are too many people in some places in big cities. Every year many people move to the cities to find jobs, to study at good schools and receive good medical care (医学救护). But sometimes these people cannot find work or good places to live in. Also it is hard to keep the cities safe and clean.

In big cities people can______.

A．go to different kinds of museums

B．see all kinds of plays and films

C．A and B