Who wants to be a hundredaire order of operations

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.

Which of these cities would be found in the most densely populated area on northern section of the map? a) beijing b) seoul c) shanghai d) tokyo

Can someone explain and give me two examples of checks and balances in usa government right three examples