ubuntu18.04 apt-get 无法下载 http:cn.archive.ubuntu.com 连接失败，apt-get换源

ubuntu18.04 apt-get 无法下载 http://cn.archive.ubuntu.com 连接失败，apt-get换源 给apt-get换源

cd /etc/apt/
sudo cp sources.list sources-original.list
sudo vim sources.list

进入vim之后直接先输入gg跳转到文本开端，再输入dG删除全文，复制粘贴以下内容并依次输入:、wq来保存退出

# 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.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse

之后输入

sudo apt-get update

之后就用apt或者apt-get继续安装要安装的包

清华源指南网址https://mirrors.tuna.tsinghua.edu.cn/help/ubuntu/