Question

这两条英语选择题分别选什么，求详细解答

He is the only one of the students who ______ a winner of scholarship for three years.
A. is B. are C. have been D. has been
Mary is one of the brightest students who form New York University.
A. graduated B. have graduated
C. had graduated D. has graduated

Answer 1

这是关于one of 的用法。如果one of +n +who 的这种结构。从句的谓语动词主要看先行词。先行词是one of 后面的复数名词。因此谓语用复数。如果在one of+n+who前面有 the only， the very ，the just....等词，此时的先行词不是one of 后的复数名词，而是the only 等词，从句的谓语动词要用单数形式。
所以第一个应该选D, 第二个应该选B，希望能帮助到你。

Answer 2

第一题意思是他是这群学生中唯一一个三年都拿到奖学金的人，who修饰的是他，而不是这群学生，所以第一题选A，完成时是错误的，students后应该加一个，

第二题玛丽是纽约大学毕业生里最优秀几个学生之一，所以who修饰的这群人，前后时态一致，所以选B