3 sentences

1. 语言是人类最重要的交际工具。

   yǔ​yán shì rén​lèi zuì zhòng​yào de jiāo​jì gōng​jù.

   Language is the most important tool for human social interaction.

   Source: Dong Chinese Dictionary

2. 韵律特征在口语交际中起着关键作用。

   yùn​lǜ tè​zhēng zài kǒu​yǔ jiāo​jì zhōng qǐ zhe guān​jiàn zuò​yòng.

   Prosodic features play a key role in oral communication.

   Source: Dong Chinese Dictionary

3. 他在商界有广泛的交际。

   tā zài shāng​jiè yǒu guǎng​fàn de jiāo​jì.

   He has extensive social contacts in the business world.

   Source: Dong Chinese Dictionary