3 sentences

1. 这种地板通过凹凸的沟槽进行拼接。

   zhè zhǒng dì​bǎn tōng​guò āo tū de gōu cáo jìn​xíng pīn​jiē.

   This flooring is joined using tongue and groove joints.

   Source: Dong Chinese Dictionary

2. 这个零件的连接头是凸的，正好可以插进那个槽里。

   zhè​ge líng​jiàn de lián​jié​tóu shì tū de, zhèng​hǎo kě​yǐ chā​jìn nà​gè cáo lǐ.

   The connector of this part is convex, so it fits perfectly into that slot.

   Source: Dong Chinese Dictionary

3. 他的眼睛有点向外凸。

   tā de yǎn​jing yǒu​diǎn xiàng wài tū.

   His eyes bulge out a bit.

   Source: Dong Chinese Dictionary