3 sentences

1. 他的颈椎最近有点疼。

   tā de jǐng zhuī zuì​jìn yǒu​diǎn téng.

   His cervical spine has been hurting lately.

   Source: Dong Chinese Dictionary

2. 长颈鹿有长长的颈部。

   cháng jǐng lù yǒu cháng​cháng de jǐng​bù.

   Giraffes have long necks.

   Source: Dong Chinese Dictionary

3. 由于长期低头看手机，他的脖颈感到非常僵硬。

   yóu​yú cháng​qī dī​tóu kàn shǒu​jī, tā de bó gěng gǎn​dào fēi​cháng jiāng​yìng.

   Due to looking down at his phone for long periods, his neck feels very stiff.

   Source: Dong Chinese Dictionary