In the past fifty years, American society has changed a great deal. Fifty years ago, most

Americans lived in small communities. They rarely moved from one area to another and knew their neighbors at least by name if not by close, personal relations. Life was so personal in those days that people often joked about it.They said that a person could not even stay home from church on Sunday without the whole town knowing about it. It was difficult to keep one's secret in a small community like that, but there was usually a sense of safety, of belonging, and of community togetherness in such places. Except for church and the local movie theater, there was not much entertainment. Some people dreamed about moving to the exciting life of the big cities, but most people were happy to live all their lives in the same community.

Few people experience this type of lifelong relationship or sense of community togetherness now. The American society is much more unsettled now; people often move from neighborhood to neighborhood, city to city, and coast to coast. It is rare to find people who have lived all their lives in one community. Because people move so frequently, they do not have a chance to get to know their neighbors. Perhaps this is also why Americans tend to have a more casual attitude about friendships than people from some other cultures; Americans are accustomed to leaving friends and making new friends. In such an impersonal society, people have lost the habit of saying hello to people they pass on the streets or in the hallways of their apartment buildings.

What is described in the first paragraph？

A．Entertainment in small towns.

B．Americans' adjustment to a moving society.

C．The life style. of Americans in the past.

D．Personal relations in small communities.