Ubuntu换源 阿里源用的血压拉满

说起来挺无语的，阿里云仓库不全
中科大源

# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.ustc.edu.cn/ubuntu/ xenial main restricted universe multiverse
# deb-src https://mirrors.ustc.edu.cn/ubuntu/ xenial main main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-updates main restricted universe multiverse
# deb-src https://mirrors.ustc.edu.cn/ubuntu/ xenial-updates main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
# deb-src https://mirrors.ustc.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-security main restricted universe multiverse
# deb-src https://mirrors.ustc.edu.cn/ubuntu/ xenial-security main restricted universe multiverse
 
# 预发布软件源，不建议启用
# deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-proposed main restricted universe multiverse
# deb-src https://mirrors.ustc.edu.cn/ubuntu/ xenial-proposed main restricted universe multiverse