your answer is c hope this helps
A flight simulator that helps astronauts prepare for a shuttle launch is an example of a Scientific Model.
Those would be called indicators , simply google them and you should find many. I'll leave some examples "bromophenol blue" "Methyl red" and "phenol red".
Combustion reaction
Key: O2
O2 is normally in a chemical formula when you are used to burn anything, so basically, anything with O2 involves burning.
It is natural and u can't by it
