2 sentences

1. 羟基是醇类分子的特征官能团。

   qiǎng jī shì chún lèi fēn​zǐ de tè​zhēng guān​néng tuán.

   The hydroxyl group is the characteristic functional group of alcohol molecules.

   Source: Dong Chinese Dictionary

2. 丙基是含有三个碳原子的有机官能团。

   bǐng jī shì hán​yǒu sān gè tàn yuán​zǐ de yǒu​jī guān​néng tuán.

   Propyl is an organic functional group containing three carbon atoms.

   Source: Dong Chinese Dictionary