音乐响起时，他们开始在舞池里跳恰恰舞。

When the music started, they began to dance the ___cha-cha-cha on the dance floor.

这首欢快的恰恰恰音乐让整个派对气氛活跃起来。

The lively ___cha-cha-cha music instantly lifted the party atmosphere.