I believe the Jurassic is the first period we ever had the other ones in not sure about
I think that i got the answer for number (30) and i think that the answer is (c) because it's George Washington and James Madison.
hope it help
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Answer:
This columns shows that partitioned ethnic groups have suffered significantly longer and more devastating civil wars. It also uncovers substantial spillovers as ethnic conflict spreads from the historical homeland of groups partitioned to nearby areas where non-split ethnicities reside
