Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.

Q: Context : HD 141937 is a star in the constellation of Libra at a distance of 109 ly. 
Answer : Libra

A: Which was the constellation for HD 141937?
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Q: Context : Dušan Majdán (born 8 September 1987) is a male Slovakian racewalker. 
Answer : male

A: Is Dušan Majdán a male or female?
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Q: Context : The Northern Railway Bridge (German: Nordbahnbrücke) is a Truss bridge over the Danube in Vienna, Austria. 
Answer : Danube

A:
What does Northern Railway Bridge cross over?
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