Your exam is coming up so soon that I doubt that doing exercises in books will make much difference on the score you get on the examination. I think that at this point it would be best to just take a step back from what you are doing and try to get the bigger picture because the exam itself is an opportunity for you to show your stuff; walk the walk and talk the talk. Show everybody what you can do with that hot rod; show them what's under the hood and make that puppy stand up and bark, that English dog of a language. Continue the good progress.