Why are commercial greenhouses use heaters on cold days?

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

The term equestrian relates to which animal? bulls cows horses pigs

The is an estimate of the fewest number of organisms a population needs to avoid extinction. this measurement will most if the number of offspring each female in the population produces increases. if the population's this measurement will most likely increase. 1 population density, minimum viable population, carrying capacity 2 decrease, be unaffected, increase 3 death rate increase, dead rate decrease