The reason a police car's higher in pitch as it approaches you, is because the truck pushes the sound waves so that the sound wavelengths infront of the truck gets shorter that's cause ?

answer and explanation;

composition refers to both the types of minerals within a rock and the overall chemical makeup of the rock while texture refers to the size and arrangement of the minerals or grains that make up a rock. both composition and texture can be used to classify rocks, such as igneous rocks. texture describes how the rock became solid or crystallized from liquid, melted rock. composition of a rock describes the minerals that make up a particular rock.