orial
lwk@qwfys:/etc/apt/sources.list.d$ cat official-package-repositories.list
# Do not edit this file manually, use Software Sources instead.
deb http://packages.linuxmint.com ulyana main upstream import backport #id:linuxmint_main
deb http://archive.ubuntu.com/ubuntu focal main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
deb http://archive.canonical.com/ubuntu/ focal partner
lwk@qwfys:/etc/apt/sources.list.d$
edit file /etc/apt/sources.list.d/cat official-package-repositories.list
lwk@qwfys:/etc/apt/sources.list.d$ ll
total 12
drwxr-xr-x 2 root root 4096 Jul 5 20:01 ./
drwxr-xr-x 7 root root 4096 Jul 5 19:05 ../
-rw-r--r-- 1 root root 512 Jul 5 20:01 official-package-repositories.list
lwk@qwfys:/etc/apt/sources.list.d$ cat official-package-repositories.list
deb https://mirrors.bfsu.edu.cn/linuxmint ulyana main upstream import backport
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu focal main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu focal-updates main restricted universe multiverse
deb http://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
deb http://archive.canonical.com/ubuntu/ focal partner
lwk@qwfys:/etc/apt/sources.list.d$
来源：oschina
链接：https://my.oschina.net/qwfys200/blog/4335973