swiftnesses

The cheetah's swiftness allows it to catch prey that other hunters cannot.

用法提示：swiftness 此处为名词，作主语，表示“迅速”这一特性。

We were amazed by the swiftness of her reply to our question.

用法提示：swiftness 作介词 by 的宾语，名词用法，强调反应速度快。

His swiftness in making decisions impressed the whole team.

用法提示：swiftness 作主语，后接 in doing sth，名词表示“迅速”的行为特征。