composure

即使在紧张的时刻，他也保持了冷静和镇定。

Even in tense moments, he kept his ___composure.

即使在激烈的争论中，她也保持着冷静。

She maintained her ___composure even during the heated argument.

在紧张的谈判中，他始终保持冷静与沉着。

During the tense negotiation, he maintained his ___composure throughout.