There are about 5 different aboriginal tribes
True
False

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.

Situation #1: imagine that you are a free black male living in columbus, oh in 1863. you have seen the recruiting poster and have been thinking a lot about whether or not to enlist in the union army. write a one-page letter (double spaced) to your mother telling her of the decision you have made about enlisting (or not enlisting). be sure to explain the reasons that caused you to make the decision.

Marcy tests a solution with a strip of blue litmus paper. the paper turns red. the solution is acidic basic neutral