This is a question I got from a reader, an anonymous reader, and the subject line just said, "Urgent," and this was the entire email: "If people had wheels and could fly, how would we differentiate them from airplanes?"
To pytanie dostałem od anonimowego  czytelnika z dopiskiem "Pilne", cały email brzmiał: "Gdyby ludzie mieli skrzydła i kółka, jak odróżnialibyśmy ich od samolotów?"