Why might a historian use periodization when writing about ancient greece?

Which of the following was not an effect of westward expansion? a. native american tribes suffered confinement on reservations. b. native americans learned new techniques of irrigation. c. many native americans died from the spread of disease. d. natural resources were depleted from misuse by white settlers.

Even though both ww1 and ww2 were in many ways the same conflict with basically the same countries facing off against each other, the way each war started was significantly different. the question is how what were the differences on how they started

What are contributions made by francis bacon