警察向市民发出告诫，要保持治安。

Jǐngchá xiàng shìmín fāchū gàojiè, yào bǎochí zhì'ān.

The police issued a warning to the citizens to maintain public order.

长辈常常对晚辈说一些告诫的话。

Zhǎngbèi chángcháng duì wǎnbèi shuō yīxiē gàojiè de huà.

Elders often give words of admonition to the younger generation.

老师对学生进行严肃的告诫，要求守纪守法。

Lǎoshī duì xuéshēng jìnxíng yánsù de gàojiè, yāoqiú shǒujì shǒufǎ.

The teacher gave the students a serious admonition, urging them to abide by the rules and laws.