What is the question to: "Milk is a white liquid produced by the mammary glands of mammals ."? The topic is Milk.
Ans: "what is in milk?"

What is the question to: "He lives in a large nest behind the 123 Sesame Street brownstone and has a teddy bear named Radar."? The topic is Big Bird.
Ans: "who plays as big bird?"

What is the question to: "Prince William, Duke of Cambridge (William Arthur Philip Louis; born 21 June 1982), is the elder son of Charles, Prince of Wales , and Diana, Princess of Wales , and third-eldest grandchild of Queen Elizabeth II and Prince Philip, Duke of Edinburgh ."? The topic is Prince William, Duke of Cambridge.
Ans: "what is prince williams last name?"

What is the question to: "The 500-year-old Roman Republic , which preceded it, had been destabilized through a series of civil wars ."? The topic is Roman Empire.
Ans: "how long did the roman empire last?"