B. match the words with the definitions
ozone layer oil spill sewage overpopulation natural resources greenhouse effect carbon dioxide recycling extinction cfcs
1. too many people
2. something such as land, minerals or natural energy that exists in a country
3.an increase in the world temperatures caused by the increased level of gases such as carbon dioxide in the air 4.the gas that is thought to prevent heat from escaping above the earth and which causes the greenhouse effect. 5.gases that protect the earth from the sun
6. chemicals used in aerosols and fridges, which contribute to the destruction of the ozone layer
7. when a species of animal or plant doesn’t exist anymore
8. a thin sheet of oil floating on water,
especially as a result of an accident to an oil-carrying ship
9.transformation of used material ( glass, cans, paper and some plastics) to be used again
10. the waste material and water from
people’s houses and from industry .