这座跨海大桥被誉为现代工程奇迹，是世界上最大的超级建筑之一。

The trans-oceanic bridge is hailed as an engineering marvel and one of the world's largest ___mega-structures.

三峡大坝是人类历史上最令人印象深刻的巨型建筑之一。

The Three Gorges Dam is one of the most impressive ___mega-structures in human history.