New York, London, Paris and other big cities are exciting places to live in. There are many good things to see and do. You can go to different kinds of museums, plays and movies. And it’s easy to get to these places by bus, taxi and subway. ① You can also buy things from all over the world.

  But there are serious(严重的) problems in big cities too. It’s expensive to live there. A kilo of potatoes may cost 2-3 euros (about 20-30 RMB) in France. With that money, we can have a good meal in a nice restaurant in China. And ② many, there, people, big, are, too, cities, in. Every year many people move to(流向) the cities to find jobs, to study at good schools and get good medical care (医学救护). So you have to wait in line when you go to many places. Living in these big cities, sometimes you may find it difficult to get a job or find a good apartment to live in. Also it is hard to keep the cities safe(安全) and clean.