substance can be used to play the news of negative and scratches on space
storage_of_weapons is hazardous_materials_storage. empty_space is fluid_substance. mercury is toxic_substance. negative_number is negative_scalar_interval. mercury_fulminate is artificial_substance. stain is artificial_substance. poisonous_gas is toxic_substance. worn_spot is spot. cans has information_on_outer_surface cavity is negative_space.