Answer:
cleaning
Explanation:
If people would clean up after themselves, the world's rivers and lakes would be clean. Water pollutants can be somewhat easy to remove by taking the trash out of them.
One of the major elements of natural selection is that all species have genetic variation. Natural selection is a process when organisms adapt better to their environment. It is an essential key in evolution. There is a change in phenotype of a population over time.
Lipids, also known as fats, play multiple roles in the body. Fats are broken down in the digestive tract to form individual fatty acids and cholesterol molecules. <span>Carbohydrates are the preferred source of energy for most of the tissues in the body, including the nervous system and the heart</span>