Ubuntu相关操作
sudo -i #进入root用户域
//修改源
1. cd /etc/apt
2. ls 找到souses.list
3. cp souses.list souses.list.backup
4. vim souses.list #按Esc 再按ggdG清空里面的内容
5. 将下面的复制到souses.list里面
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse