Which natural barrier to the north keep china isolated from other civilizations

Which of the following was a key accomplishment of the people of songhai? a. they had a strong military and became the largest empire in west africa. b. they established a center of islamic scholarship. c. they worked with iron and prospered from the gold-salt trade. d. they dominated in the trade of ivory, enslaved people, and animal skins.

Political boundaries are determined by the political party in control at all time true or false

What important race leader of the early twentieth century is being described?