Lots of them. Exams previously administered by your professor are preferable. This will help you determine how your professor drafts his or her exams. The Fowler School of Law Library maintains a number of prior exams prepared by law professors. Whenever possible, select a prior exam for which there is a sample answer on file. This will allow you to check your answer against the sample and evaluate your performance. If there is no sample answer on file, ask you professor if he she will review and comment on your answer. Do not, however, wait until right before finals to ask your professor to review your answer. The earlier you ask, the more likely your professor will have time to review your answer.