The correct answer is "a large-scale natural system such the Great Lakes".
Explanation:
Mathematical models are used in scientific investigations to study complex systems. This applies to the study of ecosystem dynamics of large-scale natural systems such as the Great Lakes. The Great Lakes comprise five lakes that in conjunction are 244,106 km2 long, with a complex ecosystem that includes invasive species, climate change, pollution, among other factors. It will be very complicated to study the ecosystem of such a large habitat without using mathematical models.
The trout because the trout affect the population of the frogs so their for if you lower the population of the trout it would raise the population of the frogs and visversa. <span />
