whistle

The referee blew his silver whistle to signal the end of the first half of the match.

(Chinese) 裁判吹响了他的银色哨子，示意比赛上半场结束。

Keep an emergency whistle in your hiking bag in case you get lost in the mountains.

(Chinese) 在你的登山包里放一个应急哨子，以防你在山里迷路。

The steam train began to whistle loudly as it approached the dark tunnel.

(Chinese) 蒸汽火车在靠近黑暗隧道时开始大声鸣笛。

He learned to whistle a happy tune while walking home from school.

(Chinese) 他在放学回家的路上学会了吹奏一段快乐的曲调。