alarm signal case

例句：

1. 1. The policeman was alarmed by the sudden noise.
   警察被突然的噪音吓到了。
2. 2. The alarm signal case was used to warn people of an impending danger.
   警报信号箱用来警告人们即将到来的危险。
3. 3. The alarm signal case was found in the attic, hidden from view.
   警报信号箱被发现在阁楼里，隐藏得很好。