更新软件源：
sudo nano /etc/apt/sources.list
deb http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid main restricted universe multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-security main restricted universe multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-updates main restricted universe multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-proposed main restricted universe multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-backports main restricted universe multiverse
deb-src http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid main restricted universe multiverse
deb-src http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-security main restricted universe multiverse
deb-src http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-updates main restricted universe multiverse
deb-src http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-proposed main restricted universe multiverse
deb-src http://mirrors.ustc.edu.cn/ubuntu-old-releases/ubuntu/ lucid-backports main restricted universe multiverse
sudo apt-get update