Run the following command to switch the software source in the Linux mint 20 system to various mirror sites in China.
- Beijing Foreign Studies University
sudo tee /etc/apt/sources.list.d/official-package-repositories.list <<-'EOF'
deb https://mirrors.bfsu.edu.cn/linuxmint ulyssa main upstream import backport
deb https://mirrors.bfsu.edu.cn/ubuntu focal main restricted universe multiverse
deb https://mirrors.bfsu.edu.cn/ubuntu focal-updates main restricted universe multiverse
deb https://mirrors.bfsu.edu.cn/ubuntu focal-backports main restricted universe multiverse
deb https://mirrors.bfsu.edu.cn/ubuntu focal-security main restricted universe multiverse
deb http://archive.canonical.com/ubuntu/ focal partner
EOF
- Tsinghua University
sudo tee /etc/apt/sources.list.d/official-package-repositories.list <<-'EOF'
deb https://mirrors.tuna.tsinghua.edu.cn/linuxmint ulyssa main upstream import backport
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
deb http://archive.canonical.com/ubuntu/ focal partner
EOF