第12题: [单项选择]According to the passage what is unknown to many people is that _______. A. the drip cup benefited light industry B. the truth about carver was twisted or concealed C. sugar-refining owes a lot to a Negro D. a Negro invented the frying pan 参考答案:C 答案解析:文章第四段说,... who in 1846 invented a vacuum pan that revolutionized the sugar—refining industry 可知,黑人对炼