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

c

Explanation era's aren't defined by time but for a duration of time eons are what make it 300 million years

during the middle ages bibles and most christian literature was written in latin i think that’s the answer you are looking for

b.lincoln had the victory he wanted for emancipation