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: Liu Bei combined forces with Cao Cao and defeated Lü Bu at the Link Information: The Battle of Xiapi was fought between the forces of Lü Bu against the allied armies of Cao Cao and Liu Bei from the winter of 198 to 7 February 199 Answer: from the winter of 198 to 7 February 199

Answer: How long did the fight last in which Liu Bei and Cao Cao defeated Lü Bu?


Question: Context: The NFL locked out its officials in June Link Information: The 2012 NFL referee lockout was a labor dispute between the National Football League (NFL) and the NFL Referees Association Answer: 2012

Answer: In what year did the NFL lock its official out in June?


Question: Context: This was completed in time for the car to be run by the factory-supported North American Racing Team in the 1961 1000 km Nürburgring. Link Information: none Answer: none

Answer:
In the 1961 1000 km Nurburgring, did the Ferrari lose to a front engine car or a rear engine car?