Which of the following statements is true? dark colors absorb less light than light colors. the angle of refraction is always equal to the angle of incoming light. the human eye can only perceive a narrow range of wavelengths. all of the above.

You exhale co2 which is produced during cellular respiration.  co2 combines with the water in your blood's plasma to make up one half of the body's most important buffer pair, carbonic acid.  the more physical activity you engage in, the more co2 your body is producing.  you can see this by putting some of the cabbage indicator in a glass and then blowing bubbles into it through a straw.  can you see a change in the color of the indicator?