Hey there,
Your correct answer to this question would be of that "<span>A statement of fact that is generally accepted to be true and universal because it has always been observed to be true."
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Hope this helps you.
~Jurgen
B - FRONTS occur when two AIR MASSES meet!
Answer: The reason why stem cell research is a big field in biology or even the world is because stem cells might be able to treat degenerative conditions as well as answering questions about human development.
Answer:
All the energy of earth comes from the Sun
