<span>C. a severe degrading of watersheds which leads to increased soil erosion and a decrease in the
quality of drinking water</span>
A pollutant is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource.
Answer:
to illustrate key points simply.
Explanation:
You first use images to back up your evidence, then secondly use them to add aesthetic value to your slide