The principle of superpostion can be used to determine :

b a mature ovary of a plant.

instead of copying and pasting things off of tests or work done on computer which im sure you did, try and read over the question carefully

the rocks are classified by the geological process they are formed by. the three main groups of rocks are igneous, metamorphic, and sedimentary. minerals are not they are classified under the chemical classes they are in. these groups include silicates, sulfates and carbonates.