the answer to ur question is eggs bc eggs come from an animal
Answer:
I think it just all exists at once, if it never is created or destroyed. It must have just appeared at the same time at some point. It doesn't exactly come from anywhere, but that's my opinion. There might be another scientific answer out there, but that's what i think. I hope this helps.
Explanation:
Answer:
the answer would be the 3rd answer
Explanation:
a half life is the time it takes for half of a radioactive substance to decay
I hope this helps :)
This solar energy conversion process is known as photosynthesis. ... At this time, the oxygen level was approximately 10% of its present atmospheric concentration. ... The presence of ozone enabled organisms to develop and live on the land.