Ubuntu 14.04 设置软件源

建议先将之前的备份，然后在编辑

cp /etc/apt/sources.list /etc/apt/sources.list.bak
vi /etc/apt/sources.list

中科大软件源

deb http://debian.ustc.edu.cn/ubuntu/ natty main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ natty-backports main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ natty-proposed main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ natty-security main multiverse restricted universe
deb http://debian.ustc.edu.cn/ubuntu/ natty-updates main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ natty main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ natty-backports main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ natty-proposed main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ natty-security main multiverse restricted universe
deb-src http://debian.ustc.edu.cn/ubuntu/ natty-updates main multiverse restricted universe

阿里云：

deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse

网易163源：

deb http://mirrors.163.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ trusty-backports main restricted universe multiverse

更新完成后记得sudo apt-get update