Answer:
D. how the body keeps its internal environment stable
Explanation:
Homoestasis is any process that living things use to actively maintain fairly stable conditions necessary for survival.
Answer:
Ecosystem engineers are species that modify their environment in a significant manner, creating new habitats or modifying existing ones to suit their needs.
Water gains energy during evaporation and releases it during condensation.
If the organism are of a similar species then it would be a population.