Answer:
Understanding the carbon cycle and how it behaves requires that we think of it as a complex dynamic system with components of the system interacting with each other in often unpredictable and emergent ways. A change in one part of a complex system can often cause a myriad of changes in other parts of the system. The Amazon forest ecosystem is a good example of a complex ecosystem currently undergoing changes.
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D because these are all nonliving things that are vital to plant growth (photosynthesis)
D because commensalism is when one organism benefits (barnacle) and one is unaffected (whale)
A because mutualism is when both species benefit
Operating living or growing water for example fish living