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As our current atmosphere formed, the concentrations of various atmospheric gases fluctuated. match each gas with the explanation that best describes how its proportion changed during the evolution of the atmosphere.

Which best expresses the radical republican philosophy of reconstruction? a. the confederate states were conquered territories that should be ruled by military governors. b. the southern states actually never left the union. c. if ten percent of the voters of a state that had seceded took an oath of allegiance to the union, then it should be readmitted as a state.

Which best describes the purpose of the south carolina exposition and protest, which was written by john c. calhoun? a) to explain why the south was nullifying the tariff of 1828 b) to describe the ways the tariff of 1828 would southerners c) to persuade northern states to rebel against the federal government d) to ask england for if the south decided to secede from the union