About the year 1740 a Whitehaven miningengineer named Spedding invented an illuminating machine called a steel mill.是什么意思_About the year 1740 a Whitehaven miningengineer named Spedding invented an illuminating machine called a steel mill.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句