An observation is defined as: "the action or process of observing something or someone carefully or in order to gain information"; an inference is defined as: "a conclusion reached on the basis of evidence and reasoning."
Answer:
Gas exchange during respiration occurs primarily through diffusion. Gas molecules move from a region of high concentration to a region of low concentration. Blood that is low in oxygen concentration and high in carbon dioxide concentration undergoes gas exchange with air in the lungs.
Explanation:
