TASK DEFINITION: Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.
PROBLEM: Context : Matthias Billen (29 March 1910 -- 1 July 1989) was a German international footballer.
Answer : 1 July 1989

SOLUTION: When did Matthias Billen's death occur?

PROBLEM: Context : Timelash is the fifth serial of the 22nd season in the British science fiction television series Doctor Who, which was first broadcast in two weekly parts from 9--16 March 1985.
Answer : Doctor Who

SOLUTION: What series is Timelash a part of?

PROBLEM: Context : Works No. 174 started a modernization programme for the ZSU-57-2 in parallel with the beginning of its serial production in 1957, but this programme was rejected due to the development of new radar-guided SPAAGs armed with small-bore autocannons and another tracked chassis.
Answer : 1957

SOLUTION:
What was the year ZSU-57-2 entered service?