始终记得为你重要的文件定期创建备份。

Always remember to create a regular ___backup of your important files.

为了安全起见，我们将数据的备份保存在不同的物理地点。

For safety, we keep a ___backup of our data in a different physical location.

系统每晚都会自动将备份保存到外部驱动器。

The system automatically saves a ___backup to the external drive every night.