Question

He is the only one of the students who _________ a winner of scholarship for three years.

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

Answer 1

当先行词前出现the only one of 时，要把one看成是先行词，即为单数。后面从句的谓语用单数。题中有一个时间段的时间状语，选择D。(想想啊，唯一一个，能用复数吗？)
当先行词前出现one of 时，就不是这情况了。如：
He is one of the students who ___have been______ a winner of scholarship for three years（是N多当中的一个。）

Answer 2

选择 D. has been
解析：
1、从定语从句中表语 a winner of scholarship，知道指的是一个人，关系代词应该指代 one，需要单数形式的动词与其保持一致。
2、从句中有表示从三年前一直到现在的时间状语 for three years， 应该用完成时态表示“三年来一直是奖学金的获得者”。

Answer 3

C
首先，本题考查的是one of 与 the only one of 的区别。前者选择be动词要用复数形式，后者用单三形式；其次，考查的是完成时与现在时的区别。这道题正好有一个时间段for three years，因此要用完成时，综合所述选择C。

Answer 4

D
who所指显然是he，he has been
他是唯一一个三年都拿奖学金的学生。

Answer 5

D. has been