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.

Context : The Carquinez Bridge refers to parallel bridges spanning the Carquinez Strait, forming part of Interstate 80 between Crockett and Vallejo, in the U.S. state of California. 
Answer : Carquinez Strait
What river does Carquinez Bridge cross?

Context : Sigmund Widmer served as colonel of infantry in the Swiss militia army. 
Answer : infantry
What organization was Sigmund Widmer involved with?

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. 
Answer : Frederik, Crown Prince of Denmark

What is Mary, Crown Princess of Denmark's spouse's name?