A single drive letter character的用法和样例：
- A mounted volume, or mount point, allows you to use a single drive letter to refer to many disks or volumes.
- There can be up to four primary partitions on a single drive.
- The letter was written on a single sheet of paper.
- And, like linear mode, the death of a single drive will bring down the entire RAID-0 volume and make it unrecoverable.