Final answer:
Carbon, hydrogen, and oxygen are the three most common elements found in living things that are important to the human body.
Step-by-step explanation:
The three most common elements found in living things that are important to the human body are carbon, hydrogen, and oxygen.
Carbon: Carbon is the building block of organic molecules and is found in all living organisms. It forms the backbone of compounds like carbohydrates, lipids, proteins, and nucleic acids.
Hydrogen: Hydrogen is essential for many biological processes. It is a component of water and is involved in energy production through cellular respiration.
Oxygen: Oxygen is required for the process of cellular respiration, which generates energy for cells. It is also a component of many organic molecules.