3 sentences

1. 无论做什么工作，都要安全当头。

   wú​lùn zuò shén​me gōng​zuò, dōu yào ān​quán dāng​tóu.

   No matter what the job is, safety must come first.

   Source: Dong Chinese Dictionary

2. 他把这块金表作为借钱的当头。

   tā bǎ zhè kuài jīn biǎo zuò​wéi jiè qián de dàng​tou.

   He used this gold watch as collateral for the loan.

   Source: Dong Chinese Dictionary

3. 面对当头而来的挑战，我们必须保持冷静。

   miàn​duì dāng​tóu ér lái de tiǎo​zhàn, wǒ​men bì​xū bǎo​chí lěng​jìng.

   Facing the challenges ahead, we must remain calm.

   Source: Dong Chinese Dictionary