Keisha suffers from post-traumatic stress disorder (ptsd). her primary symptom is being unable to relax and difficulty falling asleep. based on this description, keisha's symptoms are an example of which aspect of ptsd

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.