"What effect did Reconstruction have on blacks? Were they better off after Reconstruction than they were before the Civil War?"

Which of the following is an example of the pull factor known as economic migration? a. better educational opportunities pulling people towards a new country b. mexican laborers entering the us to work in agricultural jobs c. joining family members that are already in a new country d. crop failures driving people away from their country i am unsure on this question, i was thinking b? but i could be wrong.

In general which explains why communist revolutions did not happen

What was the result of the soviet unions actions in berlin in 1948?