Answer: It's eaither A. To understand the world around us
OR
B. To solve a problem
Explanation:
The dependant variable would be the salmon, because they depend on the water and pollution levels to give a result.
Dissolving is when the solute breaks up from a larger crystal of molecules into much smaller groups or individual molecules. This break up is caused by coming into contact with the solvent. In the case of salt water, the water molecules break off salt molecules from the larger crystal lattice.