Экология

le started building factories and many of the things they make, like cars, put a lot of harmful gases into the air. Today the air is so polluted in some places that its not always safe to breathe there. Many cities around the world have air polluted with "smog". This is so strong in some places that the air, which should be a beautiful blue, looks brown. These emis - sions have consequences for mans health, weakening the im - mune system of people.
Polluted air is not only bad for people and animals, but also for trees and plants. And in some places its even damaging farmers crops - the food we eat.
A great number of trees growing on the planet produce oxygen and clean the air. But vast forests are cut and burn in fire. Their disappearance upset the oxygen balance.
Up in the sky, above the air we breathe, theres a layer of gas called ozone. It helps us by blocking out the sun rays that can harm our skin, and by letting the rays that are good for us come through. We are lucky to have this roof. But now, because of the air pollution, the ozone layer is destroyed. The dangerous rays get through the atmosphere, causing different diseases.

Read the text and analyze it. Find on table the problems that are lit in the text.

Disappearing animals
Almost all animals, insects, and birds living on our planet need help. Every ten minutes, one kind of animal, plant or insect disappears. If nothing is done about it, over one million species will disappear in twenty years from now. They could disappear forever. During 300 years 280 species were destroyed on our planet. Every day there are more and more people living on the Earth. All these people need room to live. So they move into the places that are already homes for plants and animal