...last year I didn't = biggest mistake.
...this year, I did.
...because at least a month before the exam, you should already know the content... to the point where teachers can no longer teach you content, what I do is just ask them for things I'm not sure off. They can go off-topic sometimes, or even make the pace of a lesson very slow.
...that's how I see it. But that's just me. I did better in Biology this year than last year, because of self-studying. Always better than relying on teachers, coz that's gonna fail you.
...well, my case is that do 1 subject in 1 college. Where I do English Lang/Lit, Classics and History, I have a study leave. But for Biology, I don't (but I missed lessons for it).