As Don said, the exam is open book, so next time around, read over each question slowly and make sure you understand what it's asking before you answer. If you're unsure, search through the VATUSA Training Material (http://www.vatusa.net/training/tiki-index.php) and look for the answer. All the answers you'll need are in there.
And the exam should automatically reassign itself to you after 1 week has passed.
Best of luck with the exam, and good luck at whichever ARTCC you decide to join!