VBox enhancements are tools that allow you to share the Clipboard, mouse public, and shared folders inside and outside a virtual machine, although this option is available on the menu bar, but there is no way to use the shared clipboard if the enhancements are not installed within the virtual machine. Therefore, it must be installed.
Select Install Enhancements on the VBox menu bar. At this time VBox will automatically enhance the CD-ROM ISO file into the optical drive, but this is not a mount behavior, only to simulate the physical CD into the CD-ROM drive, this is not operational, will report a permission error, with chmod to change the authority is not working.
Using mkdir, create a mnt folder and mount the Dev/cdrom to the folder.
Run "./vboxlinuxaddition.run" directly under this folder.
Note If the run fails, an error will be required to install "Apt-get install dkms" and then install "Lsmod | Grep-i VBox "(This lsmod command does not understand why to write, do not know whether write has no effect, anyway I wrote, and then run successfully), after the installation of this command, run again vboxlinuxaddition can.
Finally remember reboot, and then the virtual machine menu selected.