Read and fill in articles. There are ___ lot of problems at beginning of new century. The problems to be urgently solved are: ethnic conflicts, growing world population and ecological crisis. The first two problems are not so vital because they are logical ones. Ecological crisis is our mutual problem. No country can be isolated and independent because we share same climate system. environment needs to be protected. Millions of people on our planet suffer air, water and land pollution: cars, factories and plants produce wastes that poison the atmosphere and cause holes in sky. Scientists first discovered hole in 1982. Now it’s getting bigger. Man-made chemicals (CFCs) destroy ozone layer. The ozone layer stops the ultraviolet radiation from the sun which causes sunburn and skin cancer. CFCs come from fridges, air-conditioners, aerosol cans and from manufacture of some plastic products. There’s another problem. We breathe out carbon dioxide. During last century we have produced a lot of it. sun warms atmosphere and then some of the heat escapes back into space. But the carbon dioxide doesn’t allow it to get out. The atmosphere becomes warmer. It is called greenhouse effect and it is dangerous for all living-beings. Some scientists think that it’ll make world hotter and change the climate all over world. Trees take carbon dioxide from air and produce oxygen. Big rainforests are very helpful. But parks and gardens in our cities also help us. We should remember that trees can help Earth and try not to destroy them. That’s why we should be kind to birds and animals, they protect large and small forests from complete destruction.