How is earths atmosphere like the ocean

Which term describes a possible explanation of, or answer to, a scientific question that is based on prior knowledge or research and that is testable?

How has our understanding of the first sentence of the declaration of independence changed over time?

“obamacare”: included a provision for government-run health insurance called “the public option.” was bitterly opposed by congressional republicans because most favored a “single-payer” plan. survived two challenges to its constitutionality. was partially repealed in 2013 in order to avert a government shutdown. led to the expansion of medicaid in republican controlled states.