What does the command mount -a do?
A. It mounts all available filesystems onto the current directory.
B. It shows all mounted filesystems.
C. It mounts all user mountable filesystems for the current user.
D. It mounts all filesystems listed in /etc/fstab which have the option auto set.
E. It mounts all filesystems listed in /etc/fstab which have the option noauto set.
題解
「mount」指令用來掛載檔案系統，「-a」參數可以掛載「fstab」(/etc/fstab)內所有沒使用「noauto」參數的檔案系統。所以答案是選項D。