Texts written by others. Very nice quiz, but unfortunately, the texts in explanations were directly borrowed from other sources (exact matches on other pages can be googled for most explanations). No credit is given which at the very least violates the Wikipedia licenses.
E.g., "The Blitz was a German bombing campaign against the United Kingdom in 1940 and 1941, during the Second World War. The term was first used by the British press and is the German word for 'lightning'." <= https://en.wikipedia.org/wiki/The_Blitz, etc.
E.g., "The Blitz was a German bombing campaign against the United Kingdom in 1940 and 1941, during the Second World War. The term was first used by the British press and is the German word for 'lightning'." <= https://en.wikipedia.org/wiki/The_Blitz, etc.