sentences: if an object falls on another object, then two objects are touching
docs: objects_fall_downward_if_there is nothing_to_support. object has surface animate_object has ability_to_move_itself dropping_object is dropping. intentionally_dropping_object is dropping_object. worthless_object is object. finding_object is performing. dropping_game_object is dropping_object. indirect_object is object. dropping_object is irreflexive_action.