In English the preposition 'to' doesn't have to be repeated.
Report it please.
It says that hegy can be both a mountain and a hill. Is that really so? If I say that I am going to the hegyhez would that imply a need for climbing gear or a nice stroll uphill?
For the hills under 300 meters we say "domb", above it we say "hegy". But in Hungary the highest mountain is 1014 meters high, so that's why we don't have so many wordds for it.
For me, the whole sentence was already filled in, I only had to click "check". ??
"To where are these nice birds flying" should also be marked correct. Best practice is to avoid finishing a clause or sentence with a preposition, although this is commonly done in colloquial English.