normally open control element

例句：

1. 1. The engineers designed the normally open control element to ensure smooth operation of the system.
   工程师们设计了这个通常开启的控制元件，以确保系统的平稳运行。
2. 2. The normally open control element was used to regulate the temperature in the factory.
   这个通常开启的控制元件被用来调节工厂的温度。
3. 3. The normally open control element is essential for maintaining the safety and reliability of the system.
   这个通常开启的控制元件对于保持系统的安全性和可靠性至关重要。