What natural boundary helps form the border between the United States and Mexico?

What was the name of the theory that said that if one country in a region fell to communism, others would surely follow? 1) domino theory 2) arms race 3) brinkmanship 4) containment theory

Africa, 1914 which statement is the best conclusion for the information presented in the map? a) european colonization had a positive impact on african nations. b) african colonization the economic growth of all european nations involved. c) by the outbreak of world war i, most of the african continent was under english control. d) by the outbreak of world war i, most of the african continent was under european control.

Which of these would be describing a developed country? a) literacy rate of 84% b) life expectancy of 58 years c) post-secondary education rate of 10% d) infant mortality rate of 3 per 1,000 births