The ways of life in many parts of the world have changed. This is the result of changes in the weather and the climate n many parts of the world.Besides this there are numbers of large factories,plants, electric power stations and railways all over the world,And today there are millions of cars and lorries on the roads.o the water and the air are already not so clean. Fires destroy the work of nature.Big forest in many places have burnt or cut down. People have always hunted valuable animals for their skins.
