raise the horn

例句：

1. 1. The bandleader raised his horn to signal the start of the performance.
   乐队指挥举起号角，示意演出开始。
2. 2. The firefighters blew their horns to alert the public about the fire danger.
   消防员吹响警笛，警告公众火灾危险。
3. 3. The announcer raised his horn to introduce the next segment of the broadcast.
   播音员举起号角，介绍下一档节目。