matter is a mean of dunes
group_of_sand_dunes is not naturally_occurring_tangible_substance. group_of_sand_dunes is naturally_occurring_tangible_substance. desert is not terrain_with_lot_of_sand. range_of_dunes is not group_of_sand_dunes. desert is terrain_with_lot_of_sand. acid_rock is rock. solid is state_of_matter. solid is not state_of_matter.