sudo vim /etc/apt/sources.list
アリ
deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal main restricted universe
multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe
multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-security main restricted
universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe
multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe
multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe
multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted
universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe
multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted
universe multiverse清華大学
deb 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 https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted
universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted
universe multiverse
中国科学技術大学
deb https://mirrors.ustc.edu.cn/ubuntu/ focal main restricted universe
multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal main restricted universe
multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-updates main restricted universe
multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-updates main restricted
universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-backports main restricted universe
multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-backports main restricted
universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-security main restricted universe
multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-security main restricted
universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ focal-proposed main restricted universe
multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ focal-proposed main restricted
universe multiverseネットイース
deb http://mirrors.163.com/ubuntu/ focal main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ focal-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ focal-backports main restricted universe multiverse
sudo apt update