Generate a correct and concise answer for the question based on the words in the context.

[Q]: Context : Between March 1942 and February 1943, Lysaght's produced 28,000 Owen Guns. 
Question : What was the year that Owen Gun entered service?
[A]: 1942


[Q]: Context : Mary, Crown Princess of Denmark, Countess of Monpezat, R.E. (née Mary Elizabeth Donaldson; born 5 February 1972 in Hobart, Tasmania, Australia) is the wife of Frederik, Crown Prince of Denmark. 
Question : What is Mary, Crown Princess of Denmark's spouse's name?
[A]: Frederik, Crown Prince of Denmark


[Q]: Context : The Champ de Mars Massacre took place on 17 July 1791 in Paris in the midst of the French Revolution. 
Question : When did Champ de Mars Massacre occurr?
[A]:
17 July 1791