How does the Earth's early atmospheric composition differ from today's composition?
a. There is little difference
b. There was no nitrogen in the early atmosphere
c. Oxygen levels have increased
d. Carbon dioxide levels have increased
Answer: C
How does the Earth's early atmospheric composition differ from today's composition?
a. There is little difference
b. There was no nitrogen in the early atmosphere
c. Oxygen levels have increased
d. Carbon dioxide levels have increased
Answer: C