在危机中,他非常镇定。
zài wēijī zhōng , tā fēicháng zhèndìng 。
He remained very calm in the crisis.
她的镇定让我印象深刻。
tāde zhèndìng ràng wǒ yìnxiàng shēnkè 。
Her calm demeanor impressed me.
要在考试中保持镇定。
yào zài kǎoshì zhōng bǎochí zhèndìng 。
You need to stay calm during the exam.