Put these sentences in the correct order. Write 1, 2, 3, etc., on the lines. The United States grows larger.
The colonies become free after the Revolutionary War.
Only Indians live in North America.
Europeans explore the Americas.
The Civil War takes place.
Jamestown is settled.

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.