Control rods are used to slow down the reaction in the reactor core when the core becomes too hot.

Which best describes how johannes kepler developed his laws of planetary motion

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?

How does kepler second law of planetary motion overthrow one of the basic beliefs of classical astronomy