noun 下载 🔗分享 燃素 The hypothetical fiery principle formerly assumed to be a necessary constituent of combustible bodies and to be given up by them in burning. Examples : "Chemists once believed that wood released phlogiston into the air as it burned. " 化学家们一度认为木头燃烧时会向空气中释放燃素。 theory chemistry substance physics science energy 与AI对话词汇游戏阅读练习