修改前记得先备份 sudo cp /etc/apt/sources.list /etc/apt/sources.bak

然后修改源配置文件 sudo gedit /etc/apt/sources.list

台湾

deb http://tw.archive.ubuntu.com/ubuntu/ karmic main universe restricted multiverse
deb http://tw.archive.ubuntu.com/ubuntu/ karmic-updates universe main multiverse restricted
deb http://tw.archive.ubuntu.com/ubuntu/ karmic-proposed universe main multiverse restricted
deb http://tw.archive.ubuntu.com/ubuntu/ karmic-security universe main multiverse restricted
deb http://tw.archive.ubuntu.com/ubuntu/ karmic-backports main multiverse restricted universe
deb-src http://tw.archive.ubuntu.com/ubuntu/ karmic main universe restricted multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu/ karmic-security universe main multiverse restricted
deb-src http://tw.archive.ubuntu.com/ubuntu/ karmic-updates universe main multiverse restricted
deb-src http://tw.archive.ubuntu.com/ubuntu/ karmic-proposed universe main multiverse restricted

北京交通大学

deb http://mirror.bjtu.edu.cn/ubuntu/ karmic main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ karmic-backports main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ karmic-proposed main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ karmic-security main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ karmic-updates main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ karmic main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ karmic-backports main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ karmic-proposed main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ karmic-security main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ karmic-updates main multiverse restricted universe

马来西亚

deb http://archive.mmu.edu.my/ubuntu/ karmic main restricted universe multiverse
deb http://archive.mmu.edu.my/ubuntu/ karmic-security main restricted universe multiverse
deb http://archive.mmu.edu.my/ubuntu/ karmic-updates main restricted universe multiverse
deb http://archive.mmu.edu.my/ubuntu/ karmic-proposed main restricted universe multiverse
deb http://archive.mmu.edu.my/ubuntu/ karmic-backports main restricted universe multiverse
deb-src http://archive.mmu.edu.my/ubuntu/ karmic main restricted universe multiverse
deb-src http://archive.mmu.edu.my/ubuntu/ karmic-security main restricted universe multiverse
deb-src http://archive.mmu.edu.my/ubuntu/ karmic-updates main restricted universe multiverse
deb-src http://archive.mmu.edu.my/ubuntu/ karmic-proposed main restricted universe multiverse
deb-src http://archive.mmu.edu.my/ubuntu/ karmic-backports main restricted universe multiverse

江苏双线

deb http://mirror.lupaworld.com/ubuntu karmic main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu karmic-security main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu karmic-updates main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu karmic-backports main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/ubuntu-cn karmic main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/ karmic-proposed main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic-security main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic-updates main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic-backports main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu/ karmic-proposed main restricted universe multiverse

日本 代码

deb http://jp.archive.ubuntu.com/ubuntu/ karmic main universe restricted multiverse
deb http://security.ubuntu.com/ubuntu/ karmic-security universe main multiverse restricted
deb http://jp.archive.ubuntu.com/ubuntu/ karmic-updates universe main multiverse restricted
deb http://jp.archive.ubuntu.com/ubuntu/ karmic-proposed universe main multiverse restricted
deb-src http://jp.archive.ubuntu.com/ubuntu/ karmic main universe restricted multiverse
deb-src http://jp.archive.ubuntu.com/ubuntu/ karmic-proposed universe main multiverse restricted
deb-src http://jp.archive.ubuntu.com/ubuntu/ karmic-security universe main multiverse restricted
deb-src http://jp.archive.ubuntu.com/ubuntu/ karmic-updates universe main multiverse restricted