The air we breathe is mainly consisted of oxygen. Air is vital to us, plants and animals. Human inhale oxygen and exhale carbon dioxide. On the other hand, plants use carbon dioxide to perform photosynthesis to convert carbon dioxide to oxygen.
Everyday human dumped rubbish into the rivers and seas. As a result, our rivers and seas are seriously polluted and we drink these water. By constantly emitting poisonous gases and fumes from factories, cars and other devices, we are threatening our environment. All of these actions caused pollution to our environment.