sentences: limestone is a kind of sedimentary rock & marble is a kind of metamorphic rock ->  limestone is a kind of sedimentary rock and marble is a kind of metamorphic rock  sedimentary rocks are formed by deposition / cementation & metamorphic rocks are formed by rocks being exposed to extreme heat and pressure ->  sedimentary rocks are formed by deposition / cementation and metamorphic rocks are formed by rocks being exposed to extreme heat and pressure  limestone is a kind of sedimentary rock and marble is a kind of metamorphic rock & sedimentary rocks are formed by deposition / cementation and metamorphic rocks are formed by rocks being exposed to extreme heat and pressure ->  limestone is a kind of sedimentary rock that is formed by deposition / cementation and marble is a kind of metamorphic rock that is formed by rocks being exposed to extreme heat and pressure  limestone is a kind of sedimentary rock that is formed by deposition / cementation and marble is a kind of metamorphic rock that is formed by rocks being exposed to extreme heat and pressure & class is a property of a rock and includes values of sedimentary / metamorphic / igneous ->  limestone and marble are different classes of rock and are formed by different methods  limestone and marble are different classes of rock and are formed by different methods & class is a measure of how a rock is formed -> different classes of rocks are formed by different methods