3 sentences

1. 混凝土需要几天时间才能完全硬化。

   hùn​níng​tǔ xū​yào jǐ tiān shí​jiān cái néng wán​quán yìng​huà.

   It takes several days for concrete to fully harden.

   Source: Dong Chinese Dictionary

2. 由于血管硬化，老人的血压一直很不稳定。

   yóu​yú xuè​guǎn yìng​huà, lǎo​rén de xuè​yā yī​zhí hěn bù wěn​dìng.

   Due to arteriosclerosis, the elderly man's blood pressure has been very unstable.

   Source: Dong Chinese Dictionary

3. 面对飞速发展的时代，我们不能让自己的思想硬化。

   miàn​duì fēi​sù fā​zhǎn de shí​dài, wǒ​men bù néng ràng zì​jǐ de sī​xiǎng yìng​huà.

   In this rapidly evolving era, we cannot allow our thinking to become rigid.

   Source: Dong Chinese Dictionary