hasn't it
前面是主从复合句,反意问句的动词和主语要和主句中的主谓语（这里是it's been found ）保持对应关系.
前肯后否,所以用hasn't it
注意：it's been found =It has been found 是现在完成时的被动语态,问句中时态要一致
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