Our surroundings are being polluted faster than nature and man's present efforts cannot prevent it. Time is bringing us more people, and more people will bring us more industry, more cars, larger cities, and the growing use of man-made materials. What can explain and solve this problem? The fact is that pollution is caused by man--by his desire for a modern way of life. We make "increasing industrialization" our chief aim. So we are often ready to offer everything: clean air, pure water, good food, our health and the future of our children. There is a constant flow of people from the countryside into the cities, eager for the benefits of our modern society. But as our technological achievements have grown in the last twenty years, pollution has become a serious problem. Isn't it time we stopped to ask ourselves where we are going--and why? It makes one think of the story about the airline pilot who told his passengers over the loudspeaker, "I've some good news and some bad news. The good news is that we're making rapid progress at 530 miles per hour. The bad news is that we're lost and don't know where we're going." The sad fact is that this becomes a true story when spoken of our modern society. Man cannot prevent the world from being polluted mainly because  _  .
the population of the world is decreasing fast people use too many man-made materials we have more and more industry we are producing more cars, trucks and buses