sudo cp /etc/apt/sources.list /etc/apt/sources.list_backupsudo
gedit /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu/ gutsy main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ gutsy-security main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ gutsy-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ gutsy-proposed main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ gutsy main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ gutsy-security main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ gutsy-updates main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ gutsy-proposed main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse
ubuntu-cn源:
deb http://archive.ubuntu.org.cn/ubuntu-cn/ gutsy main restricted universe multiverse
刷新列表
sudo apt-get update