How did the settlers of the middle colonies develop their economy?

Which statement is a good description of a model? a) models are a description of nature based only on one or two variables. b) models are testable ideas but they are not very to most people. c) models are a description of nature that predicts more accurately than real events. d) models are an approximiation of a real system that omits all but most essential variables in a system.

Describe some effects of the rise of communism in the soviet union?

On a production possibility curve, data points that fall outside of the curve represent what