Please check my answers???

4. Trade and travel among the regions of South America have been affected by
a. natural resources and vegetation
b. high mountains and dense rain forests (I picked this)
c. the Caribbean Sea and the Pacific Ocean
d. Argentina and Venezuela's relationship
7. The city of Tenochtitlan was the center of which ancient civilization?
a. Spanish civilization
b. Mayan civilization
c. Incan civilization
d. Aztec civilization (I picked this)
8. Incan civilization was located along the western coast of
a. South America (I picked this)
b. the Yucatan Peninsula
c. Mexico
d. Central America
9. Under Simon Bolivar's leadership, independent Colombia, Venezuela, Ecuador, and Panama became joined in a federation called
a. the Northern Federation
b. Gran Colombia
c. New Spain (I picked this)
d. the Incan Empire
11. Spain's two most important colonies in the Americas were
a. New Spain and Peru (I picked this)
b. Lima and Peru
c. Mexico and Central America
d. Mexico City and Lima
12. What agreement has made trade easier between Mexico, the United States, and Canada?
a. NASA
b. NAFTA (I picked this)
c. NATO
d. NAPA
13. In Belize, the official language is English, but in most Central American nations the official language is
a. Portuguese
b. Spanish (I picked this)
c. French
d. Quechua
16. One effect of rapid urbanization in Mexico is
a. an increase in jobs (I picked this)
b. a shortage of housing
c. a decrease in emigration
d. an increase in the rural population
18. Most people of South America are descended from
a. Spaniards, French, and British
b. Native Americans, Africans, and Europeans (I picked this)
c. Asians, Spaniards, and Africans
d. Native Americans, Asians, and Europeans
19. Which of the following is NOT an independent country?
a. French Guiana (I picked this)
b. Suriname
c. Guyana
d. Venezuela
20. One difference between the population of Chile and Brazil is that
a. most Brazilians live in the rain forest, while most Chileans live in the mountains (I picked this)
b. most Chileans are Roman Catholic, while most Brazilians are Protestant.
c. most Chileans live in cities, while most Brazilians live in rural areas
d. most Chileans are mestizos, while Brazilians are very ethnically diverse.