Q: What is the question to: "On June 30, 1970, the Reds hosted the Atlanta Braves in their grand opening, with Hank Aaron hitting the first ever home run at Riverfront."? The topic is Riverfront Stadium.
A: "who hit the first home run at riverfront stadium??"

Q: What is the question to: "In photography , bracketing is the general technique of taking several shots of the same subject using different camera settings."? The topic is Bracketing.
A: "what is bracketing in photography?"

Q: What is the question to: "Browser extension , which modifies the interface and/or behavior of web browsers"? The topic is Add-on.
A: "what are add ons?"

Q: What is the question to: "The definition of the world's busiest airport has been specified by the Airports Council International in Geneva, Switzerland."? The topic is World's busiest airport.
A:
"What are the busiest airports in the world?"