参考答案:I shall have left for Shanghai/I will have left for Shanghai 答案解析:[解析] 本题主要考查将来完成式。根据从句中的by(在……之前)和时间状语tomorrow可以判断主句中的谓语动词到那时将已经完成动作,所以该谓语动词应该用将来完成时。
第26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