Why are rivers so important in southeast asia?

The impact of a large asteroid comet with earth has been proposed to have caused the extinction of the dinosaurs. the impact site of this comet is in or near

These factors threaten north americas ecosystems

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.