The newspaper exposed the officer as a spy.报纸将那军官的间谍身份揭发了出来.此句中为何用介词as,它在句中无实义呀!此句中这样表达岂不更好:The newspaper exposed a spy of the officer.此句中的"of"表......的,属所属关系,应该更贴切呀!我这样理解的对不对呀?