Environmental Protection

4. A chemical added to the food to avoid its going off.
5. gases Gases which are responsible for the greenhouse effect, including carbon dioxide, methane, ozone, and the fluorocarbons.
7. rain Rain that contains a high concentration of pollutants.
8. warming An increase in the average temperature of the earth's atmosphere causing climatic change.
9. The act of preserving the environment.

1. species A species at risk of extinction because of human activity, changes in climate.
2. The collection and often reprocessing of discarded materials for reuse.
3. The cutting down and removal of all or most of the trees in a forested area.
4. The introduction of harmful substances or products into the environment.
6. Food wastes, trash, rubbish.