Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.

[Q]: Who was the main detractor of the humoral theory of immunity, oh scratch that, I mean cellular theory?
[A]: Who was the main detractor of the cellular theory of immunity?

[Q]: What combined with rising rather lowering prices to make it difficult or impossible for poor people to keep pace?
[A]: What combined with lowering prices to make it difficult or impossible for poor people to keep pace?

[Q]: What percentage of the population died in the 1625 outbreak of the Black Death no change this to what was the population of Europe in 1665?
[A]:
What was the population of Europe in 1665?