A. There were animals 3 billion years ago; they just weren't fossilized. B. Animals are warm-blooded; the ocean was too cold for animals.
<span>All planets revolve around the sun. - Incorrect. There are many planets that revolve around other stars.
</span>
A vaccine can help keep people healthy and protect them from a certain virus. For example people in the United States get the flu shot when they get this shot the vaccine wont magically get rid of the virus but rather help them fight it off and protect them in the future if they keep up to date getting the vaccine
Chromatids thats your answer to that question.
