3 sentences

1. 他那沉稳的脚步声在走廊里回荡。

   tā nà chén​wěn de jiǎo​bù​shēng zài zǒu​láng lǐ huí​dàng.

   His steady footsteps echoed down the hallway.

   Source: Dong Chinese Dictionary

2. 老人迈着沉稳的步子在公园里散步。

   lǎo​rén mài zhe chén​wěn de bù​zi zài gōng​yuán lǐ sàn​bù.

   The old man walked with steady steps through the park.

   Source: Dong Chinese Dictionary

3. 这位年轻人说话做事都很沉稳，给人一种很可靠的感觉。

   zhè wèi nián​qīng​rén shuō​huà zuò shì dōu hěn chén​wěn, gěi rén yī zhǒng hěn kě​kào de gǎn​jué.

   This young man is very composed in his speech and actions, giving off a very reliable impression.

   Source: Dong Chinese Dictionary