4 sentences

1. 苏联于1991年解体。

   Sū​lián yú yī​jiǔ​jiǔ​yī​nián jiě​tǐ.

   The Soviet Union dissolved in 1991.

   Source: Dong Chinese Dictionary

2. 苏联在1991年正式解体。

   Sū​lián zài yī​jiǔ​jiǔ​yī​nián zhèng​shì jiě​tǐ.

   The Soviet Union officially disintegrated in 1991.

   Source: Dong Chinese Dictionary

3. 前苏联在1991年正式解体。

   qián Sū​lián zài yī​jiǔ​jiǔ​yī​nián zhèng​shì jiě​tǐ.

   The former Soviet Union officially dissolved in 1991.

   Source: Dong Chinese Dictionary

4. 工人们正在将这台报废的机器解体。

   gōng​rén men zhèng​zài jiāng zhè tái bào​fèi de jī​qì jiě​tǐ.

   The workers are dismantling this scrapped machine.

   Source: Dong Chinese Dictionary