题目

    Who are these people rushing by you in the street? More than 215 million people now call America “home”, but most of them can trace their families back to other parts of the world. If you look at the names on shop windows, you will see that Americans come from many different lands. The idea that these people, who once were strangers to the United States, have lost the customs and cultures of their original countries and have become “Americans” is really not true. In fact, what exists in America is more often a kind of “side-by-side” living in which groups of people fr我国的地势特点对河流产生的有利影响有（　　）A．蕴藏着丰富的水能B．水流平缓，利于通航C．大江南流，利于南北交通D．河流流量大，含沙量小