My first exam is in 3 weeks and I have no idea how to revise- other than geog I'm doing STEM subjects and they're really straight forward to revise for. But geog is so content heavy and I really struggle with doing practice papers as I never know how to mark them, they always say "credit other valid responses" but how do I know if my response is valid??? Also I've asked my teacher for revision help but he said he's too busy to mark any practice questions we've done, and he also won't do revision sessions even though the entire class has begged him to. I'm really stressed, I want to get an A in geography but I just don't know how to revise at all!