Who did the south use as a work force? what was the ratio of southerners who owned slaves? out of that ratio , what was the percentage of those who owned slaves that had 20 or more?

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.