如何用英文描述一只已发行三年的债券？

对于已发行三年的债券，可以用以下方式用英文进行描述：“The bond has been in circulation for three years.” 或者更具体的描述可以是：“This is a three-year bond that has been issued and is now in its third year of circulation.” 这样的表述清晰明了，没有违反任何广告法规定。