3 sentences

1. 这种纸的表面非常平滑。

   zhè zhǒng zhǐ de biǎo​miàn fēi​cháng píng​huá.

   The surface of this paper is very smooth.

   Source: Dong Chinese Dictionary

2. 这种机制纸比手工纸更平滑。

   zhè zhǒng jī​zhì zhǐ bǐ shǒu​gōng​zhǐ gèng píng​huá.

   This machine-made paper is smoother than handmade paper.

   Source: Dong Chinese Dictionary

3. 由于表面磨得平滑，金属板上映出了灯火的亮光。

   yóu​yú biǎo​miàn mó de píng​huá, jīn​shǔ​bǎn shàng yìng chū le dēng​huǒ de liàng​guāng.

   Because the surface was polished smooth, the metal plate reflected the light of the lamps.

   Source: Dong Chinese Dictionary