Environmental problems

Anotações:

• Global warming is coused by the greenhouse effec. Carbon dioxide and other gases trap the sun's heat.

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• The ozon layer is layer of gas high above the surface of the earth that helps to protect it from the sun's ultraviolet radiation.

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• In recent years, large areas have been destroyed, as the trees are cut down for wood or burned to clear the land for farming.

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• Factories, power stations and motor vehicles pump large quantities of carbon dioxide and other gases into the air.

Anotações:

• Solar power is a way of using the sun's energy. We can also use  wind- power by building modern windmills. There are several types of water-power.

Anotações:

• Recycling is the processing of used objects and materials so that they can be used again.