like this?

I think .

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Our factories and homes burn coal and oil. Every year we have forest fires somewhere. Many scientists believe that the weather is changing.

The earth will perhaps be warmed by about 7℃ at the South Pole(极) and the North Pole. The ice will be melt(融化). The sea level(平面) will rise by about 7 meters. As a result, water will cover cities like London, Tokyo and New York. Some ports(港口) and towns along the coasts will disappear under water.

Some other scientists think that the dust, smoke and pollution from coal, wood and oil fires will block out(封闭) the ultraviolet rays(紫外线). Then the earth will become colder and great sheets of ice will cover Europe and North America.

When chemicals in the air mix with rain, we have acid(酸) rain. Acid rain can bring us great harm. It destroys(破坏) forests and kills life in lakes and rivers.

People are beginning to see how serious the problem is. They find it important to work with nature instead of against it. They are trying to save the earth in many different ways. But one of the most important things to do is to make people understand that saving the earth is saving ourselves.

— Pretty good. I think he ___ a great job so far.

The earth is our home and we must take good care of it. That is to say we must 1 the land, air and water clean. But man 2 a lot of pollution on earth since he first made a fire, washed his clothes in the river and threw 3 on the ground. Many years ago, pollution was not so serious 4 there were not so many people.

There was enough 5 air, land and water. When the land or the river was dirty in one place, man moved to 6 place. Man now, 7, is slowly polluting the whole world and there is neither enough clean air, nor clean land, nor clean water. The more people there are in one place,8 environment they maybe have.

Perhaps you 9 it is endless for people to produce pollution.10 , we are glad to tell you that people have come to know the danger of pollution and more and more people are working hard to protect our earth.

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