运维进行时

备份软件源：
sudo cp /etc/apt/sources.list /etc/apt/sources.list_backup

编辑软件源：
sudo gedit /etc/apt/sources.list

将里面的内容通通删掉，然后将下面的信息粘帖进去：
Archive.ubuntu.com更新服务器（欧洲，此为官方源，电信网通用户使用)：

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