如果the only one 要求
从句谓语用单数形式,only one要用复数形式.
举例:
He is the only one of the students who is never late .他是学生中 唯一不迟到的学生
因为从不迟到的学生(who is never late)是唯一的(the only one),is代表了唯一的学生,所以用单数
He is only one of the students who are never late .他仅仅是从不迟到的学生中的 一个.who are never late修饰students,学生多个,所以用are