报警器

例句：

1. 1. The alarm clock went off at 5:30 a.m.
   闹钟在早上5点半响了。
2. 2. She was so scared that she didn't want to go outside.
   她害怕得不想出去。
3. 3. The fire department arrived quickly to put out the fire.
   消防队迅速赶到扑灭了火。