Tonny is the best student of the three. In other words he is student than the other two.

问题补充：

Tonny is the best student of the three. In other words, he is student than the other two.

A. a better

B. the better

C. the best

D. a best

答案：

(答案→)A. a better

B. the better

C. the best

D. a best

解析：句意：托尼是这三名学生中最优秀的。另外，他是一名更优秀的学生比其他两名学生。分析前文是运用最高级的形式进行比较，下文是运用比较级的方式进行比较，good的比较级是better,另外指出的是一个更优秀的学生，故选A