Biggest city from different countries

Try to guess the languages with the most native speakers in the United States.

They're not better, they just have more money. Name the countries that have the highest mean household wealth per adult.

Click on every square of the world map which contains an urban agglomeration with a population of at least 10 million.

Start by naming any country that France borders. Then name any country that borders any of those countries. Then keep going until there are no more countries left to name.