spring-balanced bell gauge

例句：

1. 1. The policeused the spring-balanced bell to alert the public during emergencies.
   警方使用弹簧平衡式警铃在紧急情况下提醒公众。
2. 2. The spring-balanced bell was a symbol of safety in this old building.
   弹簧平衡式警铃是这座老建筑安全的象征。
3. 3. The new design of the spring-balanced bell is more user-friendly than its predecessor.
   弹簧平衡式警铃的新设计比其前任更用户友好。