My words of advise is to simply relax. I know that this might be asking a lot but if you can it will help immensly. Most IO's are human and understand the pressure that you have been under just to make it this far. Being from Australia my IO said that he believed that I would have only 'minor problems' with the language and that therefore the language test would not take place. He then went on to ask the ten questions - I remember the last one distinctly. He asked me to describe the geological structure of the pre-Cambrian period Californian coastline. When I replied, " I don't believe that question is on the list' his reply was, "No its not and you have passed......congratulations'