Durante gran parte de la Edad Media se había extendido en la agricultura el uso del sistema derotación bienal. Este consistía en dejar reposar la mitad de un terreno después de la cosechamientras la otra mitad era labrada. Este modelo fue sustituido por el sistema trienal que implicabadividir la tierra en tres partes y cultivar solo dos, mientras una tercera quedaba en descanso(barbecho), lo que permitió

for the 2 countries u can do china and america because america has a democratic government while china has a communist government.

a democracy is a government run by the people either by directly voting or indirectly by electing representatives. an oligarchy is a government run by a few or a small group of people. a democracy and oligarchy are similar because both in an oligarchy and an indirect democracy, a small group of induvial determine the laws for a large group of people they are different because in an oligarchy it is easier to control and they do not have to answer to a large number of people in the country, unlike a democracy where they do have to answer to a large number of people an county that is a democracy would be the united states. a country that is an oligarchy would be the china.