It's more of a case of individual questions being chosen for any of the daily/hourly quizzes, ot the global challenge, not quizzes in their entirety.
Let's say I write a quiz that has as Q1 - Which actress starred in the movie "Miss Congeniality"? Answer Sandra Bullock, pretty straightforward (actually it's pretty boring, but it's just an example!).
Okay, Q2, What was her character's name in the movie?
This can be answered if you know that I'm talking about Sandra Bullock in "Miss Congeniality" because of the previous question. However if only Q2 is selected for one of the above quizzes, no one would have any idea what the question means.
This is why questions are not allowed to be linked.
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Editor: Movies/Celebrities/Crosswords
"To insult someone we call him 'bestial'. For deliberate cruelty and nature, 'human' might be the greater insult." - Isaac Asimov