Troposphere because it is at the very top. As u delve deeper, you get to the core which is the hottest part of the earth
You need to test the hypothesis several times and record all results. Once you obtain the same results several times, I think that means its a theory
Answer:
I'm pretty sure it is B, because of natural selection
Atom
Molecule
Organelle
Cell
Tissue
Organ
Organ system
Organism