Definition (冷静)
The ability to remain composed and calm when facing difficult or stressful situations.
镇定的情绪（在困难时候）
This job requires a cool head and steady nerves.
这份工作需要冷静的头脑和稳定的神经。
This type of work demands steady nerves and lightning-fast reflexes, which is why the retirement age is usually 50.
这种工作需要稳定的神经和闪电般的反应，这就是为什么退休年龄通常是50岁。
Competitors in this event need immense concentration, not to mention strong nerves.
这项赛事的参赛者需要极高的专注力，更不用说强大的神经了。