我安装了 debian 11 Bullseye，这是我的 source.list 文件：
deb http://deb.debian.org/debian bullseye main contrib non-free
deb-src http://deb.debian.org/debian bullseye main contrib non-free
deb http://security.debian.org/debian-security bullseye-security main contrib non-free
deb-src http://security.debian.org/debian-security bullseye-security main contrib non-free
deb http://deb.debian.org/debian bullseye-updates main contrib non-free
deb-src http://deb.debian.org/debian bullseye-updates main contrib non-free
deb http://deb.debian.org/debian bullseye-backports main contrib non-free
deb-src http://deb.debian.org/debian bullseye-backports main contrib non-free
当我尝试使用 更新时apt update，出现以下错误：
Err:1 http://deb.debian.org/debian bullseye InRelease
Could not resolve 'deb.debian.org'
Err:2 http://security.debian.org.debian-security bullseye InRelease
Could not resolve 'deb.debian.org'
Err:3 http://deb.debian.org/debian bullseye-updates InRelease
Could …