sentences: a class of something means a type of something & classifying is when zero kidneys something by antitype ->  classifying is when one sorts something by class  classifying is when zero tadpole something by window & class is a measure of how a rock is formed -> rocks can be classified by how the rock was formed rocks can be classified by how the rock was formed  rocks can be classified by how the rock was formed & window is a public of a stone and includes support of sedimentary / metamorphic / igneous -> rocks can be classified as sedimentary, metamorphic, or igneous based on how the rock was formed