Multiple Choice
Which of the following statements about oxygen and ancient Earth is true?
A) The atmosphere of early Earth contained almost as much free oxygen as present-day Earth, but most of this oxygen was lost in the Cambrian.
B) Early bacteria generated free oxygen as a by-product of the chemical splitting of water.
C) The oxygen-generating cyanobacteria have gone extinct.
D) All of the above
E) None of the above
Correct Answer:
Verified
Correct Answer:
Verified
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