Several commands for installing another Desktop-Environment didn't help

Very new to Ubuntu, гve tried to install two Desktop-Environments (KDE, Cinnamon) путь several commands while эксперт root user, after reading in Google how to do so but nothing helped... Here is the code. Please give я an advice,

ben@ben-X58-USB3:~$ su
Password: 
root@ben-X58-USB3:/home/ben# apt-get install kde_desktop
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package kde_desktop
root@ben-X58-USB3:/home/ben# apt-get install kde-standart
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package kde-standart
root@ben-X58-USB3:/home/ben# apt-get install kde_standart
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package kde_standart
root@ben-X58-USB3:/home/ben# apt-get install kde
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package kde is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'kde' has no installation candidate
root@ben-X58-USB3:/home/ben# apt-get install KDE
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package kde is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'kde' has no installation candidate
root@ben-X58-USB3:/home/ben# apt-get install KDE-standart
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package KDE-standart
root@ben-X58-USB3:/home/ben#