Answer:
Humans have some stem cells, but those cells are not easily available to help with healing. Most other mammals are the same, so they aren't good at regeneration either. Amphibians and some fish have stem cells that are more easily available, and are usually pretty good at regeneration.
The answer is 'instinct'. This is innate complex behavior exhibited by an organism that is not learned. Some common examples are dogs shaking themselves dry when wet, honeybee communication via intricate dances, animal courtship behavior during mating season and the building of nests by birds.
Answer:
I would say "Water moderates Earth's climate by absorbing large amounts of heat."
Wait till someone else answers though, i am not entirely sure.