apt-get update

apt-get upgrade

root@iZ28t2p7lz9Z:~# adduser cui
Adding user `cui' ...
Adding new group `cui' (1000) ...
Adding new user `cui' (1000) with group `cui' ...
Creating home directory `/home/cui' ...
Copying files from `/etc/skel' ...
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
Changing the user information for cui
Enter the new value, or press ENTER for the default
        Full Name []:
        Room Number []:
        Work Phone []:
        Home Phone []:
        Other []:
Is the information correct? [Y/n] y

别忘了编辑  /etc/sudoers  变成SUDO用户