apt

1、先备份

sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup （备份下当前的源列表，有备无患嘛.）

2、修改更新源

sudo gedit /etc/apt/sources.list （打开源列表文件）

3、修改

deb http://mirrors.sohu.com/ubuntu/ karmic main restricted

deb-src http://mirrors.sohu.com/ubuntu/ karmic main restricted

deb http://mirrors.sohu.com/ubuntu/ karmic-updates main restricted

deb-src http://mirrors.sohu.com/ubuntu/ karmic-updates main restricted

deb http://mirrors.sohu.com/ubuntu/ karmic universe

deb-src http://mirrors.sohu.com/ubuntu/ karmic universe

deb http://mirrors.sohu.com/ubuntu/ karmic-updates universe

deb-src http://mirrors.sohu.com/ubuntu/ karmic-updates universe

deb http://mirrors.sohu.com/ubuntu/ karmic multiverse

deb-src http://mirrors.sohu.com/ubuntu/ karmic multiverse

deb http://mirrors.sohu.com/ubuntu/ karmic-updates multiverse

deb-src http://mirrors.sohu.com/ubuntu/ karmic-updates multiverse