#阿里云的软件源
deb https://mirrors.aliyun.com/ubuntu/ precise main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ precise main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ precise-security main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ precise-security main restricted universe multiverse

deb https://mirrors.aliyun.com/ubuntu/ precise-updates main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ precise-updates main restricted universe multiverse

deb https://mirrors.aliyun.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ precise-backports main restricted universe multiverse

## Not recommended
# deb https://mirrors.aliyun.com/ubuntu/ precise-proposed main restricted universe multiverse
# deb-src https://mirrors.aliyun.com/ubuntu/ precise-proposed main restricted universe multiverse

持续更新。。。。