I got this one as a "Type what you hear" task. I listened to it about five times before putting in urbs. It's just so nonsensical, and to top it off the audio has a little crackling sound right when the speaker says, "urbs." Surely the young man is not a ... what?
Um.. It said I was wrong cause I said: 'surely the man doesn't live in the city'... But the correct answer was:' surely the man isn't a city.'
That's because that's what the Latin says, the Latin doesn't mention living or being anywhere ("in the city" would be "in urbe", remember).
I got this one right by guessing. I am more likely to say, "Anden laeser avisen" than "Num juvenis urbs est" and it is more memorable. By the next time this sentence comes up, I am sure I will have forgotten it and have to guess again.