Generate a correct and concise answer for the question based on the words in the context.
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Question: Context : Statesmen of World War I is an oil on canvas painting by Sir James Guthrie, completed in 1930, shortly before Guthrie's death. 
Question : What material was used for Statesmen of World War I?

Answer: canvas


Question: Context : On November 1, 2012, it was announced by Orange County Coroners Office that Mitch Lucker had died that day from injuries sustained after a motorcycle accident at Huntington Beach, California. 
Question : What was the cause of death of Mitch Lucker?

Answer: accident


Question: Context : The Troja Bridge (2014) (Czech: Trojský most) is a bowstring arch bridge in Prague that crosses the Vltava river. 
Question : Over what river does Troja Bridge cross?

Answer:
Vltava