短语词组短语on ones guard 警惕;提防Be on your guard 发现敌人了;你们应当谨慎;你们务要儆醒regulation on door guard 门卫管理规定on -guard 副词警觉状态中staying on your guard 保持警惕be on our guard 戒备着on onehas guard 警戒on our guard 警惕on n guard 站岗;警惕 返回 on guard