deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-updates main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-updates main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-backports main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-backports main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-security main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-security main restricted universe multiverse # deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-proposed main restricted universe multiverse # deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ cosmic-proposed main restricted universe multiverse