only one of the students who are present is to speak at the meeting

题目

only one of the students who are present is to speak at the meeting
我想问下.用is是因为only还是因为句子作主语,

答案

only one of the students who are present 是主语部分,其中,who are present 后置定语从句修饰 students ；而真正的主语是only one （student ）,因此谓语动词用is
意思：会议上,只有一名出席的同学会发言.