The Age of Earth Is About ________

Q3: The time of the great extinction that

Q4: Due to a virtual absence of land

Q5: Each continent contains large "core areas" of

Q7: During the _ period, large evaporite deposits

Q8: One hypothesis for the extinction that took

Q11: During the early Paleozoic era, the _

Q52: The _ means "the Sun in the

Q54: Toward the end of the Mesozoic era,the

Q59: Bacteria that thrive in oxygen free environments

Q132: The major source of oxygen in Earth's