TASK DEFINITION: Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.
PROBLEM: Where did Mongke Khan attack the Song dynasty or rather where did he defend it?

SOLUTION:  Where did Mongke Khan defend the Song dynasty?

PROBLEM: Where does food bacteria whoopsie a pathogen come in direct contact with immune cells, antibodies and complement?

SOLUTION: Where does a pathogen come in direct contact with immune cells, antibodies and complement?

PROBLEM: The idea of neutralization no acquired immunity in jawed vertebrates is the basis of what medical treatment?

SOLUTION:
The idea of acquired immunity in jawed vertebrates is the basis of what medical treatment?