one或者one of加名词或者代词作主语时,谓语必须用单数；但one或者one of 加名词或者代词后接定语从句时,从句中谓语的数要由关系代词的 "先行词" 来决定,先行词是one时,谓语用单数,先行词是关系代词之前的名词或者代词时,谓语用复数；另外,如果one前有the或者only,谓语必须用单数：
§One has to be true to his heart.
§This is one of the cars that were damaged in the accident.(先行词是cars)
§This is the only one of books on the subject that has been written in Chinese.(先行词是one)