3 sentences

1. 工程人员正在把旧机器拆开。

   gōng​chéng rén​yuán zhèng​zài bǎ jiù jī​qì chāi​kāi.

   The engineers are dismantling the old machine.

   Source: Dong Chinese Dictionary

2. 这两个花瓶是配对的，不能拆开卖。

   zhè liǎng gè huā​píng shì pèi​duì de, bù néng chāi​kāi mài.

   These two vases are a pair and cannot be sold separately.

   Source: Dong Chinese Dictionary

3. 我迫不及待地拆开了生日礼物。

   wǒ pò​bù​jí​dài de chāi​kāi le shēng​rì lǐ​wù.

   I couldn't wait to unwrap my birthday present.

   Source: Dong Chinese Dictionary