Read them all? Make notes of which parts you don't understand and come back to them.
For English, write essays or practice paragraphs with your notes, then without your notes. Write on each major theme, character, etc. Practice.
For Economics, write essays, do actual short answer questions on each topic, make up questions in your head and find all the links between core topics/chapters. Explain each syllabus dot point to yourself, and if you can't, look at your notes, then explain again.
For maths, do a question of every single
type in each topic.
Idk what for the rest, I don't do those subjects, but I imagine business would be like commerce? For that I literally just read through everything twice and knew it all ~ as long as you understand everything along the way + practice the extended it should be fine.
If all else fails and you don't get it, just memorise it word for word. Got me far in Physics last year, but then again I dropped it for this year
