4 sentences

1. 他们在舞厅里跳起了恰恰。

   tā​men zài wǔ​tīng lǐ tiào qǐ le qià​qià.

   They started dancing the cha-cha in the ballroom.

   Source: Dong Chinese Dictionary

2. 他们在舞厅里跳了一曲伦巴。

   tā​men zài wǔ​tīng lǐ tiào le yī qǔ lún​bā.

   They danced a rumba in the ballroom.

   Source: Dong Chinese Dictionary

3. 我们在舞厅跳了一整晚的舞。

   wǒ​men zài wǔ​tīng tiào le yī zhěng wǎn de wǔ.

   We danced all night in the ballroom.

   Source: Dong Chinese Dictionary

4. 舞厅的池子里挤满了跳舞的人群。

   wǔ​tīng de chí​zi lǐ jǐ​mǎn le tiào​wǔ de rén​qún.

   The dance floor was crowded with people.

   Source: Dong Chinese Dictionary