Type 'easy' or 'hard' to begin the quiz. Easy is a 15-degree grid, hard is a 10-degree grid. Then, try to name the SECOND LARGEST city in each grid square. To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period). You are given a score from 0 to 100 based on your answer's population compared to the 2nd largest city accepted in that square (100 being you named the 2nd largest city). If you guess the largest city it will be based on the ratio of the 2nd largest city's population to the largest.
At the end of the quiz the 2nd largest city will show in each unanswered square, and for those answered the 2nd largest city will be listed next to your score if you didn't answer it.
Quiz Takers 
Democratic Republic of Congo is not working. Why is that?
Just use ‘DRC’
how is Denmark wrong if it specifically says including dependent territories?
It borders Canada via Hans Island.
Doesn’t Sweden border Denmark via bridge (and isn’t Denmark larger than Sweden when Greenland is included)?
Bridge borders (unless they are causeways) do not count.
Got it. How do you differentiate between a bridge and a causeway? I assume the Bahrain/Saudi Arabia link is a “causeway?”
Yeah, same with Singapore/Malaysia. It’s a judgment call.