deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free # deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free # deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free # deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free deb https://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-security main contrib non-free # deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-security main contrib non-free