Quiz of the Year: 52 weeks 52 questions, part three

It's the third part of the Magazine's quiz of the year.

Test your recollection of 2015 over four days with four sets of 12 questions - themed on the lines of "who?", "what?", "why?" and "where?" - and a four-part puzzler. Today it's "why":

Users of the BBC News app tap here to take the quiz.

In addition to the questions above, we're also posing an extra puzzler - one photograph for each four parts of the quiz, all adding up to a single answer. Below are the first three of our pictures:

Part four of our quiz will be published tomorrow. If you missed the first parts, catch up with them here and here.

The solution to the four-part bonus question will be published in a special edition of the BBC News Magazine newsletter on Christmas Eve - subscribe here to get it sent to your inbox. You can suggest answers on our Facebook page.

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