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.

Context: He graduated from the Air Command and Staff College in 1961 Link Information: none Answer: none
How many people graduate from the Air Command and Staff College in a year?

Context: Ptacek was born in East Berlin to a family of Czech and German descent. His family fled East Germany for the United States Link Information: none Answer: none
Comparing Ptacek's country of origin to the country to which he moved at age five, which has the lowest longitude?

Context: De Boer became a Member of the House of Representatives after resignation of Joop Bakker, taking office on 16 February 1972 Link Information: De Boer took a medical leave of absence on 11 October 1982 after which Minister of Health and Environment Til Gardeniers-Berendsen Answer: 6

What is the age difference between the man De Boer replaced in February of 1972 and the man who replaced De Boer during his medical leave of absense?