Can someone please answer this question for me?!? I need it ASAP

2. given that most biochemical (other than coal) rocks react with hydrochloric acid, what does that tell you about organisms?

Aboy jumps into a cold swimming pool and his body tempature goes down hus muscles ,blood vessels

Which is a function performed by stem cells in the skin a. replacing lost skin cells b. making cells for the intestines c. growing new organs d. differentiating into brain cells plz apex