sentences: vacuum is formed by leaf weathering
docs: gaseous_form_of_water is steam. pandurate_leaf is simple_leaf. dust_in_air is form_of_pollution. convection is natural_process. dead_grass_leaf is natural_inanimate_thing. phosphate_weathering is erosion. vacuuming_carpet is vacuuming. dentate_leaf is leaf. formed is well_formed. dissolution is natural_process.