Which sentence describes energy flow through a natural system? A strong wind blows across a Midwestern prairie. The wind forces the blades of a wind turbine to rotate. As the blades spin, the turbine converts mechanical energy to electrical energy. The electricity generated by the wind turbine is used to power nearby homes.

The correct answer is - A strong wind blows across a Midwestern prairies.

An energy flow through a natural system is when we have no human interference or any man made objects in the process. A strong wind that blows across a Midwestern prairie is a nice example of this. We have a natural unmodified by humans environment through which a natural phenomenon is bringing energy flow. The energy flow will of course operate in different manner and have different effects compared to the ways in which the humans would have used it. The strong wind in the prairie will bring in lot of small particles, sediments, with its energy and deposit big portion of them in the prairie, thus making it more fertile.