根据文章内容，选择正确的答案。
   New York，London，Paris and other big cities are exciting places to live in. There are many interesting things to see and to go to. You can go to different kinds of museums，plays and films. You can also buy things from all over the world.
   But there are some problems in big cities too. It is expensive to live there and there are too many people in some places of big cities. Every year many people move to the cities to find jobs，to study at good schools.
   But sometimes these people can't find work or a good place to live in. Also it is hard to keep the cities safe(安全的）and clean.
   Some people enjoy living in big cities，others do not. Before moving to a big city，they should think about the problem of living there.

中共十八大报告指出，人民代表大会制度是保证人民当家作主的根本政治制度。要善于使党的主张通过法定程序成为国家意志，支持人大及其常委会充分发挥国家权力机关作用，依法行使立法、监督、决定、任免等职权，加强立法工作组织协调，加强对“一府两院”的监督，加强对政府全口径预算的审查和监督。材料告诉我们（  ）

①要坚持党对人民代表大会的领导   

②人大代表行使立法、决定、监督等权力

③人民代表大会是我国的立法机关   

④其他国家机关对人大负责，接受人大监督