第26题: [单项选择]______ so many efforts in such a short period of time. A. Never have any student made B. Never have a student made C. Never has any student made D. Never did a student make 参考答案:C 答案解析:本题考查句子结构。当带有否定意思的副同放在句首时,其后的句子要倒装;时间状语为in a short period of time,用完成时;student为单数,用has。该句意为:从没有一个学生能在
第27题: [单项选择]所谓麻花钻头又称为() A. 平钻头 B. 扭转钻头 C. 直槽钻头 D. 中心钻头 参考答案:B