Random questions in test mode. Yeah it'll hurt you somewhat on subjects you haven't reviewed as yet, but you want to keep your brain fresh on all topics, rather than getting stagnant on topics you studies 3 weeks ago, and you'll see where your weakness lie. Plus, you're going to have to accept that on the exam, there are going to be a lot of "WTF" questions, so working on your strategy of how to handle those is going to be important (eliminate obvious wrong answers, analyze remaining answers in the context of the question, which answer seems more likely, etc). Bring the pain now, so you don't get frazzled by it on the exam.