解决 is not in the sudoers file this incident will be reported ubuntu

该问题必须在Ubuntu的恢复模式下解决，具体步骤如下：

1. Go into the Ubuntu recovery model
2. Choose "Drop to root shell prompt"
3. $mount -o remount,rw /
4. $sudo nano /etc/sudoers
5. change to:
    root ALL=(ALL) ALL
    yourusername ALL=(ALL) ALL
6. ctrl+o;ctrl+c
7. restart pc.