Answer:
A you use apparent magnitude to find the absolute magnitude
I believe the water treatment stated above is micron filtration. Micron filtration is a water treatment method where water is filtered through screens that have microscopic holes. The holes are measured in microns and the smaller the hole the more contaminants can be removed.
The indispensable chemical element is carbon.
It depends on which macromolecule you are referring to. As examples:
Protein monomers are amino acids.
DNA monomers are nucleotides.
Carbohydrate monomers are monosacharides.
Lipid monomers are fatty acids and glycerol.
