Organisms compete for the resources they need to survive- air, water, food, and space. In areas where these are sufficient, organisms live in comfortable co-existence, and in areas where resources are abundant, the ecosystem boasts high species richness.
The circulatory system takes the carbon dioxide from the cells to the lungs and the respiratory system expels ir.
The answer to your question is H2O
I think it is called mechanical digestion. Or alas, chemical digestion. One of those. Or both!
Hope helps-aparri
(thank yous are welcome)
The answer is d according to study soup
