Higher history

Hi - for The British unit we learnt issues 1-5 and for U.S.A we’re doing issues 1-3 and issue 5.
I don’t really understand how you can “drop an issue” but would it be okay to only learn the reasons essays for Britain? Since all the U.S.A issues we’ve done are reasons, i feel more confident with them and I’d feel like I’d mess up since only 2/9 essays we’ve ever learnt are judgement essays.