Problem: A diptych is a painting or altarpiece of how many panels, commonly hinged together?
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A: two

Problem: Who has twice been Prime Minister of Italy - from 1996 to 1998 and from 2006 to 2008?
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A: romano prodi

Problem: Which cells form the middle layer of plant leaves?
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A: mesophyll

Problem: How many yards are there in a chain?
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A:
22