QUESTION: Generate a question with a factual answer?

ANS: Who produced Rabbit of Seville?

QUESTION: Generate a question with a factual answer?

ANS: How much fuel did electric train used less than diesel in the middle of 1970 in USSR?

QUESTION: Generate a question with a factual answer?

ANS: Where do Afro-Spaniards come from?

QUESTION: Generate a question with a factual answer?

ANS:
How long can it take to reach the equilibrium ratio?