some buildings are made of limestone which is a primarily calcium carbonate a _ over time _ rain react with the carbonate and the building are damaged

Plzz hurry im being timed during times of vigorous physical activity, muscles require a constant supply of oxygen. how does the body respond to these needs? a. breathing rate and heart rate both decrease. b. breathing rate and heart rate both increase. c. heart rate decreases, but breathing rate remains stable. d. breathing rate increases, but heart rate remains stable.

Pepsin is an enzyme in the stomach that breaks polypeptides into amino acids. pepsin functions best at a ph of around 1.5. what would be the most likely result if the ph of the stomach were increased to 5

Hey me with this one❤☺❤ how do you say that a cell also has a life span and death like an organism? give one example.