3) Metamorphic rocks are igneous or sedimentary rocks which have been changed by heat, pressure or chemical action.
(3) Metamorphic rocks; are; igneous or sedimentary rocks which have been changed by heat, pressure or chemical action) (igneous or sedimentary rocks; have been changed; by heat, pressure or chemical action)
3) Metamorphic rocks igneous or sedimentary rocks
are have been changed
igneous or sedimentary rocks which have been changed by heat, pressure or chemical action
by heat, pressure or chemical action