biliard ball problem

例句：

1. 1. The biliard player was playing a beautiful piece on the piano.
   那位球拍演奏家正在钢琴上演奏一首美妙的曲子。
2. 2. The violinist played a melody that perfectly matched the violoncello's sound.
   小提琴手演奏的旋律与大提琴的声音完美匹配。
3. 3. The pianist and the violoncello were performing a duet together.
   钢琴家和大提琴手一起表演了二重奏。