In this task, you're given a context, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both context and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the context or linked information.
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Question: Context: On 17 April 2010, the president of German airline Air Berlin, in an interview with the newspaper Bild am Sonntag, stated that the risks for flights due to this volcanic haze were nonexistent, because the assessment was based only on a computer simulation produced by the VAAC. Link Information: On 17 April 2010, the president of German airline Air Berlin, in an interview with the newspaper Bild am Sonntag, stated that the risks for flights due to this volcanic haze were nonexistent Answer: 3548000

Answer: How many subscribers did the newspaper Bild am Sonntag have the year that the president of German airline Air Berlin, in an interview with the newspaper stated that the risks for flights due to this volcanic haze were nonexistent?


Question: Context: the California Rugby Union successfully petitioned the United States Olympic Committee (USOC) to enter a team at the 1920 Summer Olympics Link Information: none Answer: none

Answer: What year was the committee that accepted the California Ruby Union's petition found?


Question: Context: the extension of the City and South London Railway (now part of the Northern line) from Clapham Common to Morden. Link Information: none Answer: none

Answer:
How long was the Clapham Common to Morden extension?