Having a positive experience of an empty nest is most strongly influenced by

Many members of the civilized tribes farmed

What is the role of communication within groups of people with different backgrounds?

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.