question: what requires smooth surfaces?
choices.text: volume suspension bridges Formula 1 racing gravity density research and development amphibians animals in Class Aves
choices.label: A B C D E F G H
formatted_question: what requires smooth surfaces? (A) volume (B) suspension bridges (C) Formula 1 racing (D) gravity (E) density (F) research and development (G) amphibians (H) animals in Class Aves