A、The population of elderly people. B、Nuclear weapon. C、Standard of living. D、Violence in crime. D

During the past decade, there has been a multifold increase in violent crimes throughout the world. Not only has there been a frightening increase of murders and rapes, but chances of being attacked and robbed have grown so that the elderly avoid leaving their apartments.
    The exact cause of this horrifying development has not been found. Some sociologists feel that the growth of crime on TV is related with the growth of violence on our streets. Others blame the constant threat of complete destruction from nuclear explosives. If the world is going to be blown up, why not enjoy yourself fully!
    Regardless of the cause or causes, a fundamental change in attitude among people is easy to see. Years back, the old saying "Practice what you preach" was a prevalent one. People had moral standards that they could follow: people were concerned about their fellow human beings.
    Today, people have become "I-centered." They are more interested in achieving immediate, selfish pleasures. The best advice they can give in the rare instances when they do is "Do what I say, not what I do." They are saying, "There are moral principles to follow if you want to, but don’t use me as a guide since I no longer follow them."
    The major difference that I see in the quotations points out the tragic change in our morality and social ways. Until people once more learn to replace "I" with "we," we shall continue to move toward destructive self centeredness.