What protected the United States from becoming involved in European conflicts

Which of the following is an example of one of the successes of the marshall plan? a. a few eastern european countries decided to turn to democracy. b. western european economies were stronger than they had been before wwii. c. borders between western and eastern european countries shifted. d. eastern european countries eventually took part in the plan. ( answer in the format above so i can understand)

Which factor was a major cause of the great depression of the 1930?

What was the primary goal of pre-historic man? a. cultural adaptations b. obtaining food c. developing settlements d. peaceful cohabitation