23. explain, step-by-step, the mechanism by which pct renal tubule cells secrete hydrogen ions and reabsorb filtered bicarbonate ions (indirect reabsorption of bicarbonate ions).

rising temperatures because when water vapor in the air is cooled, it condenses. it turns back into a liquid and attaches to dust particles in the air. these very small water droplets group together to form clouds

if you know your abc's you should be able to get your answer or just use google