What were three major commodities traded across the African continent in the Medieval period? asap

missouri compromise of 1820 which prohibited slavery

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copernicus finished the first manuscript of his book, "de revolutionibus orbium coelestium" ("on the revolutions of the heavenly spheres") in 1532. in it, copernicus established that the planets orbited the sun rather than the earth. he laid out his model of the solar system and the path of the planets.