Everything that you'll be asked to use in your experiments is found on the shelf.
Navigate the shelf
The shelf has three sections:
You can toggle between these shelves by clicking on each label along the bottom of the shelf.
View object names
To see the name of an object, hover your mouse on it.
Move the shelf
Move the shelf up or down by clicking on the surface, holding down your mouse, and releasing when it's at the desired height.
Move objects from the shelf
To grab an object from the shelf, just click on it, hold your mouse down, drag it to the bench, and release.