1.Tyrannosaurus Rex Lived in the Mesozoic Era
2.The largest mass extinction happened in the Paleozoic Era
3.Life exploded for the first time in the Precambrian Era
4.The Chicxulub crater in the Cenozoic Era
The correct answer is B. Oxygen.
Oxygen, as a part of the atmosphere, also participates in UV protection, besides being necessary for breathing.
He discovered that finches in different environments had different shaped beaks
Answer:
We need more information to answer.
Explanation: