Why is the coastal crossing theory of migration hard to prove or disprove?

Brainliestt asap!me : ) describe the difference : capitalism vs. communism

The 20th amendment, also called the lame duck amendment, decreased the amount of time between the presidential election and the inaugration of the new president. what are the advancements that allowed for this amendment?

Which of these did the soviet union do in 1961? it built a wall through berlin to keep people from moving to the west. it used force to destroy a wall the united states had built in berlin. it convinced the british and french to merge their zones in berlin with the soviet zone. it threatened to bomb berlin if the united states did not leave within 30 days.