instruction:
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.
question:
Context : Matthias Billen (29 March 1910 -- 1 July 1989) was a German international footballer.
Answer : 1 July 1989
answer:
When did Matthias Billen's death occur?

question:
Context : ''Restful Place'' focuses on a curved limestone bench and above it is an arched bronze and glass canopy.
Answer : limestone
answer:
What is the surface of Restful Place made of?

question:
Context : Based on the 1932 memoir I Was a Spy by Marthe Cnockaert, the film is about a Belgian woman who nurses injured German soldiers during World War I while passing intelligence to the British.
Answer : Marthe Cnockaert
answer:
The I Was a Spy is based upon what?