It was an old gameshow, very old that I do not remember what it is about.
Also, it is a Vietnamese lesson at school: about the structure like "Tôi là Huy", each part can be an answer for question "Who?".
Just curious. Do you even use this question? :)
In English its fairly common...networking at a business event, you turn to your friend and ask, "Alright, who is who?" More specifically we'd ask "Who is everyone?" But same, same, lol...
Not really. Duolingo seems to specialize in language usage no one actually uses.