3 sentences

1. 看这匹马的口齿，正当壮年。

   kàn zhè pǐ mǎ de kǒu​chǐ, zhèng​dàng zhuàng​nián.

   Looking at this horse's teeth, it is in its prime.

   Source: Dong Chinese Dictionary

2. 他平时很注意保护口齿卫生。

   tā píng​shí hěn zhù​yì bǎo​hù kǒu​chǐ wèi​shēng.

   He usually pays great attention to oral hygiene.

   Source: Dong Chinese Dictionary

3. 这位播音员口齿伶俐，吐字清晰。

   zhè wèi bō​yīn​yuán kǒu​chǐ líng​lì, tǔ​zì qīng​xī.

   This announcer is articulate and has clear enunciation.

   Source: Dong Chinese Dictionary