哨子

例句：

1. 1. The boy was playing the xylophone with his friends at the park.
   男孩和他的朋友们在公园里用木琴演奏。
2. 2. She blew a whistle to signal the start of the race.
   她吹了一声口哨来示意比赛开始。
3. 3. The musician played a melody on the flute that made everyone smile.
   音乐家用长笛演奏的旋律让每个人都笑了。