Help me answer this please answer all questions and add number so i know what answer goes where

Explain in detail the events that led to the fall of the soviet union. explain the importance of the foreign policy shift from brinkmanship to détente during the cold war.be sure to include evidence to support your answer describe the challenges to nation-building that exist in africa today .

The social contact theory states that

'nepal have varied vegetation as climate and landforms'. justify the statement