I think the answer is D. Circulatory because this system helps to get the absorbed nutrients throughout the whole body
When animals are fighting over resources the number of one animal might decrease because the other animal would've tried to kill it and stay alive
when there is competition the population size of one animal might decrease while another increases<span />
i believe its true but idk lol hope this helps :)
Is is plants that provide food, provide shelter, and prevent erosion, since plants are a major food source for many animals, as well as cover from rain and weather.