deb http://debian.ustc.edu.cn/ubuntu/ lucid main multiverse restricted universe deb http://debian.ustc.edu.cn/ubuntu/ lucid-backports main multiverse restricted universe deb http://debian.ustc.edu.cn/ubuntu/ lucid-proposed main multiverse restricted universe deb http://debian.ustc.edu.cn/ubuntu/ lucid-security main multiverse restricted universe deb http://debian.ustc.edu.cn/ubuntu/ lucid-updates main multiverse restricted universe deb-src http://debian.ustc.edu.cn/ubuntu/ lucid main multiverse restricted universe deb-src http://debian.ustc.edu.cn/ubuntu/ lucid-backports main multiverse restricted universe deb-src http://debian.ustc.edu.cn/ubuntu/ lucid-proposed main multiverse restricted universe deb-src http://debian.ustc.edu.cn/ubuntu/ lucid-security main multiverse restricted universe deb-src http://debian.ustc.edu.cn/ubuntu/ lucid-updates main multiverse restricted universe