Every time baby Miriam says "Da-da," her parents smile at her and give her lots of attention. She responds by saying "Da-da" more frequently. The smiles and attention are for her learning to talk.

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.

Why are people in history willing to fight in conflicts against a more powerful oppressor?

Thomas jefferson was alarmed by the fierce debate over warning americans about its threat to national unity. 1.) slavery 2.) the powers of congress 3.) the missouri compromise 4.) escaped slaves