I have a JC friend who fail his H1 General Paper, and he is
still promoted to JC2, with the requirement to pass his General
Paper within a few months time, which I have forgot the exact dates
he told me.
Anyway, why would you want to fail your subjects since you have
gone so far into JC?
To be precautious, pass all your subjects, it is a
test before you face your ‘A' levels.