当定语从句的先行词为one of +n.时,定语从句谓语动词需要与先行词短语中的n.在数上保持一致.但是如果定语从句的先行词是 the only one of +n,则定语从句的谓语就要与先行词短语中的one保持一致.例如:
She is one of the girl students who are going to have a medical examination.(她是要参加体检的女生之一)
She is the only one of the girl students who is going to have a medical examination.(她是女生中唯一要参加体检的)