Can I please just emphasise the importance of not dwelling too much on SACs? It is more than fine to lose a couple of marks on each of your SACs- it's never going to kill your chances of achieving a 40+ study score. As long as your ranking within your class is decent, there is no reason why you can't achieve your desired score. It's the exams that are the most important in terms of your study score- and even then, you can afford to lose quite a number of marks and still achieve a 40+ study score. If you receive a SAC back and the result isn't as desirable as you would of liked, don't panic. Just stay focused and persevere in the hope that you will improve on your next SAC. But most of all, don't get too caught up in the numbers- work hard, be consistent and you will reap the benefits.