How does being surrounded by mountains affect civilizations? *

Which answer best explains the overall impact of the chicken on native american populations in the new world? negative; it destroyed much needed grain crops neutral; it was not well adopted by native americans insignificant; other animals were more quickly accepted positive; it brought a good source of protein to the native american diet

List three reasons why explorers began to explore new, and old areas. [[ps: doesn't explicitly say where. i think it's more in general.

How w. e.b. dubois wanted to improve the social and economic situation that existed for african americans during the early 19th century?