她的语气听起来很镇定，但手却微微发抖。

Tā de yǔqì tīng qǐlai hěn zhèndìng, dàn shǒu què wēiwēi fādǒu.

Her tone sounded calm, but her hands were slightly trembling.

火警响起时，他依然保持镇定，冷静地疏散了大家。

Huǒjǐng xiǎngqǐ shí, tā yīrán bǎochí zhèndìng, lěngjìng de shūsàn le dàjiā.

When the fire alarm went off, he still remained calm and calmly evacuated everyone.

只有在内心真正镇定的时候，人才能做出理性的选择。

Zhǐyǒu zài nèixīn zhēnzhèng zhèndìng de shíhou, rén cáinéng zuòchū lǐxìng de xuǎnzé.

Only when one is truly calm inside can one make rational choices.