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 fought in Operation Barbarossa, the German invasion of the Soviet Union, and claimed his first aerial victory on 8 August 1941. Link Information: none Answer: none
How many days did Operation Barbarossa last?

Context: In 1972 he became the first Professor of Music at Sussex University Link Information: none Answer: none
How many students were enrolled at Sussex University the year Mitchell became the first Professor of Music there?

Context: EBV appears to cause all nonkeratinizing nasopharyngeal carcinomas and some cases of lymphoma, including Burkitt's lymphoma—the association is especially strong in Africa—and Hodgkin's disease. Link Information: none Answer: none

How fatal is Burkitt's lymphoma?