The Precambrian time refers to the time 4.5 billion to 542 millions year ago. This period is characterized by having reduced atmosphere and included reduced compounds. Scientists believed that atmosphere at that time was devoid of free oxygen and CO2 was present in excess. Before the complex life evolved on the Earth, the Precambrian Earth's ocean contained dissolved carbon dioxide.
They have evolved into the best length for their environment.
Answer:
Answer in order: C, A, B
Explanation:
But I'm not the brightest at this subject, but what I did is just observed what I thought the answers were thoroughly by using the keywords and letters and then matching them together to make sense. I remember doing this, but let me know if it's wrong!
