backup air gap device

例句：

1. 1. The backup system is designed to protectthe main system in case of failure.
   备份系统旨在在主系统故障时保护主系统。
2. 2. We need to back up ourdata regularly to prevent loss in case ofa system crash.
   我们需要定期备份数据，以防系统崩溃导致数据丢失。
3. 3. The backupplan was put into action immediately after thepower outage.
   电力中断后，立即执行了备份计划。