【正确答案】 C

【答案解析】[听力原文]
Richard: Hello, Robert. I haven"t seen you for a long time. How are things going with you?
Robert: Not too bad. I"ve read a book on environmental pollution recently. I become more aware of the problems facing us.
Richard: That"s true. With the development of technology, pollution is becoming an urgent issue facing us.
Robert: Especially the automobile, you know, the automobile contributes a lot to air and noise pollution.
Richard: Yes. We are now living in quite a bad environment. We breathe the polluted air. We drink the polluted water. We eat the polluted foods.
Robert: Many diseases today are caused by pollution.
Richard: So now we should do something about the serious pollution if we want to live a better life.
Robert: That is just what I am thinking. The book says in many parts of the world, people become more aware of the problem, and they apply new technology to solving the pollution problem.
Richard: You mean there is still hope for the future. But I just want to know what technology will help with pollution control.
Robert: Well. A variety of choices. The book I"ve read says that certain types of bacteria can help control some pollution problems.
Richard: Oh, How interesting! I thought bacteria just caused diseases. How could they help control the pollution.
Robert: That"s not true. Some scientists have found that certain strains of bacteria can "eat" petroleum products, such as oil and gasoline.
Richard: Oh! Do tell me how it works.
Robert: They ingest the petroleum and excrete hydrogen and oxygen, leaving a clean environment behind them.
Richard: In this case, air can be much cleaner. Could they use those little bugs to clean up big oil spills?
Robert: That"s for sure. They have been proven to be the most successful method of cleaning the land-based oil spills and are also useful for marine spills.
Richard: Wow. How amazing! Are there any other types of pollution those microbes like to eat?
Robert: Yes. they have been used to remove arsenic from the sludge produced by gold mining operations.
Richard: Perhaps those bacteria will eventually save the world.