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