although it has been before

Your intriguing problem has not, as far as I know, been explored by economists before, although it has been discussed by artists.

据我所知，之前还没有经济学家研究过你提出的这个有趣的问题，但艺术家却有过这类讨论。

Although the photo has been published before, Mr Blair's hand gesture was digitally removed from it by the press agency which supplied it, out of respect for the Prime Minister.

尽管这张照片之前被公开过，但出于对首相先生的尊重，当时提供照片的新闻社对照片中布莱尔的手势进行了数位技术处理。

Although the phrase was used by this country's founders to denote equality before the law, it has also been interpreted to mean equality of opportunity.

尽管这句话被国家缔造者们用来预示法律面前人人平等，它也被解释为机会面前人人平等。