电梯安装了自动防故障装置，在电力中断时会缓慢降落到最近楼层。

The elevator has a ___failsafe that causes it to descend slowly to the nearest floor during a power outage.

电梯系统配有紧急制动作为安全备用方案。

The elevator system has an emergency brake as a ___failsafe.

这个安全系统设计了防故障机制，即使失灵也不会造成危险。

The security system has a ___failsafe mechanism to prevent hazards even if it malfunctions.