It's really puzzled me about "I don't believe that you're a girl! :)"
It's true that a girl should depend on herself in today's world, maybe I should pay more attention to English from now on .Thanks all the people above!
As my tradition, I should say:"I don't believe that you're a girl! :)";
And then I should say "just do what you wanna do", don't let somebody else to decide the future of your own!"; I think you totally understand what I 'm talking about~~~