英语八下课文

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 your bowl all come from trees . And I suppose you also enjoy 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 into the air . How many people are there in your class , Judy ?

JUDY: Forty-six .

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 15 air 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: Are 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 destroying our best fighters against pollution.

Almost everyone today uses electricity in one way or another. It is hard to imagine what life in our cities would be like without it. Electricity lights streets and buildings, and warms people and animals. It heats food in cookers and cools it in refrigerators. It drives trains and works traffic lights and lifts. It also works the machines in factories that make all kinds of goods. Everyday wonders such as computers and televisions use electricity to bring entertainment and news to millions of families. In villages and on farms, electrical machines milk the cows and chop their food. They also cool the milk and churn the butter. Indeed, electricity find as much as work to do in the countryside as it does in the cities.

Daisy was in the bathroom. She was brushing her teeth and the tap was on.

Water was pouring into the washbasin and vanishing down the drain.

"Turn that tap off, 'a voice said loudly. Daisy froze. She looked around, but saw no one. 'Turn that tap off. You're wasting water, 'the voice sounded impatient.

This time Daisy obeyed. 'Who ... who are you? 'Daisy's voice was faint.

'I'm a drop of water. It's not easy for me to get here. Do you know where I'm from?'

'From the tap, I suppose, 'said Daisy.

'Yes, but before that?' the voice said.'A few days days ago,I was floating comfortably in a cloud in Jiangxi, enjoying the view. Then the cloud dropped me into a stream and I sped down the mountain into the Yangtze River. the Yangtze River carried me to a lake. I relaxed there for a few days, and then I travelled a long way and ran into the Huangpu River. Then it was time to get cleaned up.'

'Cleaned up?'Daisy sounded puzzled.

'Yes. I was dirty after my journey so they took me to a water treatment works.

They gave me a thorough cleaning and added a few chemicals to me. Then I travelled in the pipes under the streets. I waited there until you called me,and here I am.'

Daisy said, 'So this is the end of your journey.'

'No.When you've finished with me,I'll go to a sewage plant. Then they'll pump me into the riverand I'll be back in the sea again.'

'Again?'

Yes.That's where I came from in the first place. Remember not to waste me or pollute me. I'm precious,like liquid gold.See you.'

'Wait a minute.What do you mean by liquid gold?'But there was no reply. The water had gone. Daisy came out of the bathroom. Her brother said,'Who were you talking to?' 'To the water,'Daisy said.

Sometimes you're strange, Daisy,'her brother said.

Dear friends:

Trees are our friends. They work hard for us. They cool our cities and clean the air .They also give out oxygen for us to breathe. Trees reduce sound pollution in cities and make cities more beautiful. Without trees, the soil would be washed away and there would be no food for us to eat. Without trees, it would get too hot for us to live on earth. Without trees, we would die.

Trees also provide a lot of things for people. They provide food. They also supply material for houses ,furniture and paper products. Some trees even provide important ingredients for medicine.

In the last 200 years, more than half of all the trees on earth have been destroyed. We need more trees!

Trees for Life is making a difference. To help protect our environment, we plant trees and take care of them. we need more people to join us in this project. We want to plant 100 million trees in the next 10 years. If you want to find out more about us, please send us an e-mail at *********************.

From

Trees for Life

The oceans cover 2/3 of the Earth, but ocean water is salty. That is to say, most of the water on the Earth is not drinkable!

90% of all the water on the Earth that human beings can drink right now is underground. It is very easy to pollute groundwater. For example, 4.5 litres of paint or about 1 litre of motor oil can seep into the Earth and pollute 1,125,000 litres of drinking water!

A leak that fills up a coffee cup in 10 minutes will waste over 13,500 litres of water in a year. How much water is that? You would have to drink 65 glasses of water every day for a year to get that much water!

If you leave the water running while you brush your teeth, you might waste 22.5 litres of water. That is enough to fill 65 cans of soft drink!

If you leave the water running while you wash the dishes, you might waste 135 litres of water—enough to wash a whole car!

Believe it or not, the water we flush down our toilets starts as fresh water! Each time you flush, your toilet uses about 9 to 15 litres of water. But it does not have to!

A shower usually takes at least 5 minutes. So every day, you could use 112.5 litres of water taking one shower. In a year, that is almost 45,000 litres of water!

A bath uses even more water than a shower—about twice as much. A bath can easily use 225 litres of water