qrepolist:
deb http://q4os.org/q4repo q4os-3-0-cn main
deb http://q4os.org/qtderepo buster main
deb http://ftp.debian.org/debian/ buster main contrib non-free
deb http://security.debian.org/debian-security/ buster/updates main contrib non-free
deb http://ftp.debian.org/debian/ buster-updates main contrib non-free
