According to a book I have, it should be "Por onde". Are both acceptable? Do they have the same meaning?
Aonde = where is the bus going? (What is it destination?) / por onde = which ways will the bus go by?
That... makes sense! Thanks. In this sentence, then, either should be accepted.
Obrigado paulenrique! I'm actually fine with the different meanings of the pronouns as so far they seem identical to the Spanish 'este/ese/aquél', etc. - it's the inconsistency in Duolingo's translations that is sometimes frustrating. I don't see any reason why in this sentence only 'this' should be accepted but 'that' is wrong. If they just accepted both 'this' and 'that' for 'ese' throughout all levels I think they'd save themselves a lot of bother..