Answer: creating an ozone layer to shield life from UV rays
Cynobacteria or blue green algae is the strain of bacteria, which was able to produce oxygen in the primitive earth as a result of photosynthesis. The abundance of oxygen in the atmosphere formed the ozone layer in the upper atmospheric layers, these layers are protective enough to provide a shield against the harmful UV radiations incident on earth coming from the sun.
I say D but if it’s wrong I’m so so sorry
Answer:
The answers that apply;
Researchers found cosmic microwave background radiation, which is a heat imprint left over from the big bang.
A redshift of light emitted by stars and galaxies indicates the universe is expanding
A primordial form of helium gas was found by the Endeavor space shuttle
Big Bang theory is a theory that endeavors to explain the origin of the universe. It stipulates that the universe exploded from a singularity and continues to expand today
Explanation:
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