他在学术研究方面取得了重大突破。

He made a significant breakthrough in his ___academic research.

这个讨论纯粹是理论上的，没有实际应用价值。

The discussion was purely ___academic with no practical application.

这位学者在哈佛大学任教已有十年。

The ___academic has been teaching at Harvard University for ten years.