What separates an eon into eras?
a) changes in rock layers
b) spieces extinctions (changes in types of organisms)
c) 300 million year chunks
d) types of plants and animals

Do you believe that unity of purpose and belief are what made the american colonies strong, or do you believe that societies whose citizens were compelled to interact with people of differing beliefs were the most successful, based on the history

Brainliesttt ! : ) -global military, political, and psychological responses to terrorism?

What mountain range is located near 60*n and 60*e