| A | B |
|---|
| fossil fuel | oil, natural gas, or coal which are an important part of the world's energy supply |
| softwood | wood of evergreen trees, often used in buildings or making furniture |
| infrastructure | system of roads and railroads that allows the transport of materials |
| permafrost | permanently frozen lower layers of soil found in the tundra and subarctic climate zones |
| taiga | large coniferous forests |
| smog | thick haze of smoke and chemicals |
| pollutant | chemical and smoke particles that cause pollution |
| czar | title given to the emporers of Russia's past |
