How do you do - in English is an official greeting - it is not necessary to answer it. But on question Как дела? Russians can answer in short or long form. Anyway, "How do you do" is more formal than "Как дела?" or "How are you doing?"
I can't write that in Russian as I have a English keyboard. Is there any way I can pass levels when I can't even type the letters? Duolingo is really fun and the people in the community are great, but I cant pass these levels because I can't type the words. Please help :(