Translation of "Fluency" in Chinese

Fluency in English is a must.

流利的英語是必須的。

I'm amazed at your fluency in English.

你流利的英语让我很吃惊。

Fluency in English is a very marketable skill today.

流利的英語在今天是一種十分搶手的技能。

I was amazed at the fluency with which the boy spoke French.

那個男孩的一口法語流利得有點兒不可置信。