Josie partially filled a graduated cylinder with water. She then dropped a rock into the water. The illustration below shows what happened to the level of the water inside the graduated cylinder, 70
70
60
60
50
50
40
30
10
What is the volume of the rock?
6ml
10 ml
35 ml
40 ml

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?