Undo

Choosing Undo from the Edit menu will reverse or "undo" the most recent action that resulted in a change to the document. For example, if you accidentally deleted a graph, you can select "Undo Delete" and your graph will reappear. Multiple levels of undo (up to 16) can be set in Preferences, meaning you can reverse up to 16 actions on the page. Note that the text of this item will change to describe the type of action that will be undone, e.g. "Undo Move" or "Undo Deletion."

The text of the Undo option changes to "Can't Undo" if you cannot reverse your last action.