"Do you know the bridges of Saint Petersburg?"
Translation:Вы знаете мосты Петербурга?
I have to report that Duolingo doesn't see 'Ты знаешь' as a good beginning of this sentence.
That's "the bridges in Saint Petersburg" (в + prepositional). The exercise says "of Saint Petersburg" (genitive).
"Ты знаешь мосты в Санкт Петербурга" was originally given as the correct answer. Now Duo will only accept "вы знаете мосты в Петербурга." ????
It's weird that it was given as the correct answer. As far as I know, в Петербурге means "in Saint Petersburg". The exercise says "of Saint Petersburg", I assumed it required the genitive (without в).