cp sources.list sources.list.backup vi /etc/apt/sources.list
#网易的源（163源，无论是不是教育网，速度都很快）
deb http://mirrors.163.com/ubuntu/ precise main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ precise-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ precise-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ precise-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ precise main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ precise-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ precise-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ precise-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse
#台湾源（台湾的ubuntu 更新源还是很给力的）
deb http://tw.archive.ubuntu.com/ubuntu precise main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu precise-security main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu precise-updates main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu precise-backports main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu precise-proposed main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu precise main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu precise-security main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu precise-updates main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu precise-backports main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu precise-proposed main restricted universe multiverse
#搜狐更新服务器
deb http://mirrors.sohu.com/ubuntu/ precise main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ precise-security main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ precise-updates main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ precise-proposed main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise-security main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise-updates main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise-proposed main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise-backports main restricted universe multiverse
#中国科学技术大学更新服务器
deb http://debian.ustc.edu.cn/ubuntu/ precise main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ precise-backports main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ precise-proposed main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ precise-security main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ precise-updates main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ precise main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-backports main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-proposed main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-security main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-updates main multiverse restricted universe
sudo apt-get update