作者：沪江英语 2011-04-05 09:06
READING: Pollution Fighters
Judy is collecting some facts for a class project on pollution. She is interviewing Doctor Ray, a scientist, about trees.
JUDY Why are you so interested in trees, Doctor Ray?
DR RAY They're the biggest and oldest living things on the earth, Judy.
JUDY Yes, but what good are trees? They make streets more beautiful and less noisy, but what else can they do?
DR RAY Well, the wood in your pencil, the rubber on the end of your pencil, the paper in your notebook and the fruit in you bowl all come from trees! And, I suppose you also enjoying breathing pure, cool air.
JUDY Of course.
DR RAY Then you must thank trees for that too. They take harmful gases from the air, and release oxygen back into the air, How many people are there in your class, Judy?
DR RAY Well, one and a half hectares of trees could produce enough oxygen to keep your whole class alive and healthy for a whole year.
JUDY That's wonderful!
DR RAY Trees cool the air as well as clean it. They are natural air conditioners. Three trees can do the job of 15air conditioners running almost all day.
JUDY You certainly know a lot about trees, Doctor Ray.
DR RAY Thank you, Judy, but I don't, really. Scientists are only now beginning to understand them. For example, when insects attack a tree, it can warn its neighbours. The trees can then protect themselves by producing a chemical that makes their leaves taste nasty. And some trees can join their roots together underground, and pass food and water to each other. Trees are communicating with one another, but we don't know how.
JUDY And trees in danger?
DR RAY In great danger. We cut down and burn millions every year, but we replace hardly any of them. We are destorying our best fighters against pollution.