位置：/etc/apt/sources.list
cn99源：
deb hardy main restricted universe
multiverse
deb hardy-security main restricted
universe multiverse
deb hardy-updates main restricted
universe multiverse
deb hardy-proposed main restricted
universe multiverse
deb hardy-backports main restricted
universe multiverse
deb-src hardy main restricted universe
multiverse
deb-src hardy-security main restricted
universe multiversedeb-src hardy-updates
main restricted universe multiversedeb-src
hardy-proposed main restricted universe
multiversedeb-src hardy-backports main
restricted universe multiverse保存，退出
sudo apt-get update
sudo apt-get dist-upgrade
