Answer: The third answer.
Explanation: It's the 3rd answer because the lungs take in the air the n distribute throughout the body, helping the circulatory system flow.
Primary sources are original materials/information on which other research is based. It includes journal articles of original research, conference papers, dissertations, technical reports, and patents. Primary sources are also sets of data, such as health statistics, which have been tabulated, but not interpreted.
Answer:
The Digestive System
Explanation:
The digestive system of the human body is made up of several organs that work together to break down food so it can be used in the body. Similar organelles in the cell are endoplasmic reticulum, ribosomes, and the golgi body.
Answer:
An electron in an excited energy level of an atom will always drop to lower energy levels, emitting very specific wavelengths of light in the process.