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.

[Q]: 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
[A]: How long did the fight last in which Liu Bei and Cao Cao defeated Lü Bu?


[Q]: Context: ceremonies include the Ndut (rite of passage) Link Information: There are two main types of Ndut initiation rites. The first concerns the circumcision for Serer boys whilst the second concerns the initiation of Serer girls. Serer religion and culture forbids the circumcision of Serer girls (female genital mutilation). Only Serer boys are circumcised. Serer girls receive their initiation through njam or ndom (the tattooing of the gums). Preparation for the initiation starts early in childhood. In many cases, boys are circumcised when they reach 13 years old. However it is not uncommon for some to be circumcised when they are 19 to 26 years old. Likewise, Serer girls receive their initiation when they are 11 to 18 years. Answer: the circumcision for Serer boys
[A]: What is performed during the rite of passage?


[Q]: Context: On February 7, 1917 Satō was assigned command of the 2nd Special Task Fleet Link Information: none Answer: none
[A]:
How old were Sato's staff that were to become future geneerals when Sato was assigned command of the 2nd Special Task Fleet?