Why classification is needed ?

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

the law of original horizontality explains:   why rocks appear in layers. correct answer: b the law suggests that all rock layers are originally laid down (deposited) horizontally and can later be deformed.   the principle is used by geologists to make assumptions about the relative ages of sedimentary rocks.