The current is swiftest in the middle of the river.

河当中水流最急。

《新英汉大辞典》

The gazelle is one of the swiftest and most graceful of animals.

瞪羚是最敏捷最优雅的动物之一。

youdao

And instantly with a thunder of hoofs and beating of wings a dozen or so of the swiftest creatures disappeared into the gathering darkness.

话音刚落，顿时响起一阵雷鸣般的马蹄声和翅膀扑棱声，约有十几只动作最迅速的动物消失在暮色中。

youdao

The reason for that I think is that the early times in which these civilizations arose saw all kinds of dangers coming, and the most--the swiftest, the least suspected, the one that could come upon you overnight came from the sea.

在我看来原因是,在这些文明所诞生的早期世界危机四伏,而来的最迅速,最难以预测,最可能,一夜之间骤然降临的灾难,正来自于海上

耶鲁公开课 - 古希腊历史简介课程节选

But they are a conservative bunch at the ECB and not the swiftest in making changes.

FORBES: A 'Yen' For Your Thoughts

The 28-year-old American simply ran away from the swiftest the rest of the world had to offer.

CNN: THE OUTSTANDING PERFORMANCE

Capitalism is a system wherein capital, i.e. money and credit, finds the smartest and swiftest businesses or entrepreneurs.

FORBES: Keep Geniuses Out of the Post Office