What are some of the dangers that volcanoes pose to human populations?
a. destruction of property from lava flow
b. destruction from mud flows
c. lung problems from ash and toxic gases
d. all of the above

Which of the following best describes the purpose of a nation’s boundaries? a. to limit the movement of goods and people b. to make it easier for cartographers to create maps c. to make the movement of goods and people easier d. to prevent other countries from invading territory