https://mirrors.tuna.tsinghua.edu.cn/help/debian/
/etc/apt/sources.list
debian11 例子：
# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
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
# deb https://security.debian.org/debian-security bullseye-security main contrib non-free
# # deb-src https://security.debian.org/debian-security bullseye-security main contrib non-free
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