"Who studies at home?"
Translation:Quis domi studet?
It should also be accepted now, but unfortunately it takes some time for the changes we make in the Incubator to be active for users (sometimes as long as two weeks).
Still, please report (with the button in the lesson, not in the discussion) if it's not accepted, it's still possible something got missed!
domi, the locative form of domus, is part of a group of nouns (cities, towns, small islands, domus, one or two other ones) that is used with the locative case to denote the location.
urbs is not apart of those nouns so we make use of in + the ablative (urbe) to express the location.