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When I type
sudo apt-get install rails I get the message:
media change: please insert the disc labeled 'Ubuntu 12.04.3 LTS _Precise Pangolin_ - Release amd64 (20130820.1) in the drive '/media/cdrom/' and press enter
I am new to Linux and I have the installation CD in the drive, but I have no idea what disc it is asking for and I'm not sure what
/media/cdrom/ means. All I have is the installation CD and it is in the only optical drive I have.