The land in Mexico City is subsiding over time. What is the primary cause of this problem? A.
too many dams being built along rivers
B.
deforestation caused by cutting down trees
C.
too many buildings being constructed
D.
underground aquifers being overpumped

How do hearths affect cultural diffusion? a. a hearth is the destination of cultural diffusion. b. a hearth divides a cultural region in two. c. a hearth is the beginning point of cultural diffusion. d. a hearth is the means of cultural diffusion. e. a hearth is the meeting point of two diffuse cultures.