premise: how can i make bread crumbs?
hypothesis: Preheat oven to 250 degrees F (120 degrees C).    Using tongs, place bread slices directly on oven racks. Leave in oven until hard and golden brown, about 30 minutes; darker if you prefer. ...    Crumble slices into a large bowl until reduced to fine crumbs, or place in bowl of food processor and process until fine.