Which of the following events separate geologic time into eras and periods?
the creation of new ocean ridges
the appearance and disappearance of volcanoes
the appearance and disappearance of groups of organisms
the number of earthquakes occurring at that time

Explore the ways that boundaries influence identity, interaction and exchange. things to consider: what is the race/ethnicity. how easy is it to interact/trade with others.

Which contenents can easily trade by traveleing the meddetaranian sea

This image shows a volcanic eruption in hawaii with lava flowing into the sea. which statements best describe this eruption? check all that apply. its magma is high in silica. its magma has low viscosity. its lava came from a quiet eruption. its lava sets fire to everything in its path. its lava came from an explosive eruption.