Why do historians divide history into eras?

Explain how tectonic plate movement creates geological events and features.

The chart shows the marginal cost and marginal revenue of producing apple pies. what most likely will happen if the pie maker continues to make additional pies? the marginal costs will continue to rise, increasing the total cost, while the marginal revenue remains the same, decreasing the profit. the marginal costs will continue to fall, decreasing the total cost, while the marginal revenue remains the same, increasing the profit. the marginal costs will continue to rise, increasing the total cost, while the marginal revenue remains the same, increasing the profit. the marginal costs will continue to fall, decreasing the total cost, while the marginal revenue remains the same, decreasing the profit.

Montesquieu suggested dividing government into