Can you not say "я забув яка ЦЯ країна?"
Wow that was a quick turnaround! Thanks SergioRudio! I was wondering if I had missed something in the lessons or if what I had written down was actually right.
I can't get why my answer is incorrect. I typed "Я забулА" instead of "Я забуВ". I am a native speaker and am aware of the fact that in this sentence both variants must be correct.
You should use "Report a problem" button to report missing translations. Your report would have allowed us to check your translation. I suppose you had a typo in your answer, because "я забула/забув, яка це країна" is accepted.