3 sentences

1. 这项工作已经安排了专人负责。

   zhè xiàng gōng​zuò yǐ​jīng ān​pái le zhuān​rén fù​zé.

   A specific person has been assigned to be responsible for this task.

   Source: Dong Chinese Dictionary

2. 这头母牛正处于分娩期，需要专人照看。

   zhè tóu mǔ​niú zhèng chǔ​yú fēn​miǎn qī, xū​yào zhuān​rén zhào​kàn.

   This cow is about to give birth and needs special care.

   Source: Dong Chinese Dictionary

3. 这些重要的原始旧档都由专人负责保管。

   zhè​xiē zhòng​yào de yuán​shǐ jiù dàng dōu yóu zhuān​rén fù​zé bǎo​guǎn.

   Special personnel are responsible for keeping these important original archives.

   Source: Dong Chinese Dictionary