从所给的词中选出10个词，并用其适当形式完成下面的短文。
easy，hard，buy，help，many，before，tired，sometimes，problem，high，safe，beautiful，different
New York，London，Paris and other big cities are interesting places to live in．There are 1 interesting things to see and to do．You can go to 2 kinds of museums，plays and films．You can also go shopping to 3 things from all over the world．
But there are serious（严重的） 4 in big cities，too．The cost（费用）of living is 5 ，and there are too many people in some places of the big cities． Every year many people move to the cities because they can 6 find work there．But 7 these people can't find work or a good place to live in．Also too many people in a small space make it 8 to keep the cities 9 and clean．
Some people enjoy living in big cities，others do not． 10 people move to a big city，they should think about the problems of living there．
Key:
（D） 1．many 2．different 3．buy 4．problems 5．high 6．easily 7．sometimes 8．hard 9．safe 10．Before
