12 thinking: read the story again. put the sentences in order.
cap
they want to play football with some c liam and jake are at the park
boys.
d the boys take off their caps, scarves
b the dogs run away with the boys'
and jumpers
clothes.​

Environment - a set of components of the environment, natural and man-made natural objects and man-made objects.
Components of the environment - land, minerals, soils, surface and ground water, air, flora, fauna and other organisms, as well as the ozone layer of the atmosphere and near-Earth space, providing a set of favorable conditions for the existence of life on Earth.
Pollution - into the environment of matter and (or) energy, property, location or number of which have a negative impact on the environment.
Contaminant - a substance or mixture of substances, the number and (or) concentrations exceed established for chemical substances, including radioactive and other substances and microorganisms standards and have a negative impact on the environment.
Air pollution - a really serious problem. Air is composed of oxygen, nitrogen, water vapor, and, thanks to our civilization, of a variety of toxic particles. The more of these particles in the air is, the less room is left in the atmosphere for oxygen.
   The problem of air pollution is not limited to the space outside. The air inside our homes and offices can be as dangerous to your health. The main source of pollution - cigarette smoke, but it is not the only one. Toxins are allocated even when you just cook. Every time you scratch the Teflon non-stick coating is allocated enough toxins to kill a canary.
 Greenhouse effect, which we all have been associated with the phenomenon of global warming, caused by toxic gases. The main enemy of clear atmosphere - methane. It is released from the decomposition of sewage.
Greatly affects our waterways. In every neighborhood, in every city there drain sewer, storm water from the highways and municipal enterprises directly into the river. Everything goes into the water, passing minor cleaning steps.

My native city is Rostov-on-Don. It is the capital of the Don area. It was founded in 1749. It is situated on the right bank of the river Don.

In the past Rostov was a small town with small population. But now the territory of Rostov-on-Don is 380 square kilometres and the population is more than one million people.

Our city is a big industrial, scientific and cultural centre in the South of Russia. The plant “Rostselmash” is known not only in our country but abroad as well.

The largest scientific and educational establishment is the Rostov State University, which was founded in 1915 and now has more then ten faculties.

In Rostov there are four theatres: Gorky Drama Theatre, Musical Comedy, Puppet Show, Theatre of Young Spectators. The Gorky Theatre is surrounded by a large park named after the October Revolution. It is one of many parks and gardens which make Rostov a green town and where Rostovites like to walk on a nice sunny day.

During the Second World War Rostov-on-Don was occupied twice (1941 and 1942). The war cost Rostovites huge losses in life. That is why in the city there are a lot of monuments devoted to the war years and people who gave their lives for our peaceful life.

Rostov-on-Don is a large transport centre. It is not only a big knot of railways and airways but it is also the port of five seas (the Baltic, the White, the Caspian, the Black and the Sea of Asov).

Nowadays Rostov-on-Don as many other cities and villages in Russia is undergone the process of economical changes. But we hope that in some years people will be able to overpass all the difficulties and Rostov-on-Don will occupy its place of one of the biggest industrial cities of Russia.