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,黑人对炼糖业有