Kepler fine-tuned copernicus’ heliocentric model
determining that the planets rotate on an ellipse
determining a model to measure distances between planets
developing the theory that stars did not rotate around the sun
developing a globe that would demonstrate the rotational axis.

thurgood marshall

explanation: in 1954, thurgood marshall and a team of naacp attorneys won brown v. board of education of topeka, kansas. in this landmark decision, the supreme court held that segregation in public education violated the equal protection clause of the fourteenth amendment.

the installment plan of the 1920s, an arrangement that allowed people to buy what they wanted with a small down payment and pay off the rest in monthly installments, provided americans a way to own what they did not have the money to buy.