deb http://cn.archive.ubuntu.com/ubuntu/ trusty main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
转自： http://www.tuicool.com/articles/AFRzUjI