a short cut on desktop on gnome3

[abdelkader belahcene <abelahcene@gmail.com>]

Hi, 
I am trying to be familiar with gnome 3, 
So I installing from debian testing the gnome 3,
It seems good, but sometimes I am lost, for example, I want to put a file on the Desktop, like drag it from the usb to the screen!! as usual, it didn't work !!!

another case I used to add button on the bar just by clicking on the topbar menu to add it, the right click is not working ??!!

How to enable it?? is it possible??
thanks for help