Sir isaac newton revolutionized the way people understood the universe in the seventeenth century when he proved that the a) earth revolves around the sun. b) planets revolve around the sun. c) planets are held in place by an invisible shield. d) sun's gravity keeps the planets within their orbits.

although the crusades failed to capture jerusalem, they had several major impacts on western europe. they increased the authority of the king: sometimes nobles died in battle without leaving an heir in which case the king got their land. kings passed taxes to pay for the crusades.

because the vietnam war was fought in an especially brutal and untraditional way