What are the factors that led to the fall of the soviet union?

Ineed with what i should write for my research paper. my topic is history of slavery. 1800 words. all i need is what to write in each paragraphs. like when the research paper has titles for each paragraph and it explains the tile in each paragraph. for example when did slaverh begin? why did it begin like an outline.

Which major change took place in nigeria in 1999?

Plz where was the inca civilization located? a. in and around the andes mountains of south america. b. central america in southern mexico. c. the caribbean islands. d. the central valley of mexico.