I could be completely wrong, but... Aren't GCSE's those tests that students take here when they are like 15-16 years old? And then A-levels are tests taken at 17-18 years old? I read somewhere (probably on here!) that A-levels would be equivalent to the high school diploma in the US, so the grade would be looking at your high school grades for those subjects. I think the A-level would supercede the GCSE, wouldn't it?
Hee hee - I could be talking completely out my ar*e, but as no one had responded to you yet, Pebs -- I wanted to offer something.
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I'm sure Mindy knows! Mindy?