Please amend this quiz ASAP for consistency! Aztec and Inca were accepted by themselves and autocompleted as Aztec empire and Inca empire, yet Ottoman and British weren't accepted, apparenly because I didn't add "empire" at the end. Pick one way or the other, always ask for the word Empire or never, otherwise this just becomes infuriating instead of a nice quiz.
This would have been a good quiz (and I would've gotten four more correct answers) if I had known that I had to include "empire" in the answer. Change it!