deb [arch=arm64] http://cn.ports.ubuntu.com/ubuntu-ports/ focal main restricted deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal main restricted
deb [arch=arm64] http://cn.ports.ubuntu.com/ubuntu-ports/ focal-updates main restricted deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal-updates main restricted
deb [arch=arm64] http://cn.ports.ubuntu.com/ubuntu-ports/ focal universe deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal universe
deb [arch=arm64] http://cn.ports.ubuntu.com/ubuntu-ports/ focal-updates universe deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal-updates universe
deb [arch=arm64] http://cn.ports.ubuntu.com/ubuntu-ports/ focal multiverse deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal multiverse
deb [arch=arm64] http://cn.ports.ubuntu.com/ubuntu-ports/ focal-updates multiverse deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal-updates multiverse
deb [arch=arm64] http://cn.ports.ubuntu.com/ubuntu-ports/ focal-backports main restricted universe multiverse deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
deb [arch=arm64] http://ports.ubuntu.com/ubuntu-ports focal-security main restricted deb [arch=amd64] http://security.ubuntu.com/ubuntu/ focal-security main restricted
deb [arch=arm64] http://ports.ubuntu.com/ubuntu-ports focal-security universe deb [arch=amd64] http://security.ubuntu.com/ubuntu/ focal-security universe
deb [arch=arm64] http://ports.ubuntu.com/ubuntu-ports focal-security multiverse deb [arch=amd64] http://security.ubuntu.com/ubuntu/ focal-security multiverse
➜ sources.list.d cat proposed.list deb [arch=arm64] http://ports.ubuntu.com/ubuntu-ports/ focal-proposed main restricted deb [arch=amd64] http://archive.ubuntu.com/ubuntu/ focal-proposed main restricted