The fact "A round brush is useful for cleaning a narrow bottle." is illustrated with the story:1. Marlena found an old, tall, narrow bottle in the creek bed.2. It was full of mud.3. Marlena tried to rinse the mud out in the creek, but the bottle neck was too narrow for the mud to flow out.4. After trying to get the mud out of the bottle with a stick, she decided to give up and take the bottle home for her mother to clean.5. Her mother used a round brush called a bottle brush with a long wire stem on one end to clean the mud out of the bottle.