"镇静安神"通常用英文表达为"calm and composed"或"calm and collected."这个表达来自于英语中的形容词"calm,"意思是镇静的，平静的，安静的。"Composed"意思是沉着的，镇定的，而"collected"意思是收起来的，集中的，沉着冷静的。

下面是一些例句：

She remained calm and composed during the presentation, even when she was asked difficult questions. (她在演讲期间保持镇静沉着，即使被问到了困难的问题。)

He was able to keep his cool and remain calm and collected during the emergency. (他在紧急情况下能够保持冷静，保持镇定。)

She always manages to stay calm and composed, no matter what challenges she faces. (无论面对什么挑战，她总是能够保持冷静沉着。)

He was able to maintain a calm and collected demeanor, even when he was under a lot of pressure. (即使在很大压力下，他也能保持冷静沉着的态度。)