Translation:Do you know?
Am I the only one who doesn't see how this makes sense in English? "Know" requires an object, "do you know?" is not something any native speaker would ever say. "Don't you know?" maybe as a phrase, but not "do you know?".
Instead we would say "do you know xyz thing/(how to) verb/person/place/etc". And I've looked at the meaning of 知道, yet it still doesn't make sense to me in English.