TASK DEFINITION: Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.
PROBLEM: What does Mnemiopsis er the Beroe eat?

SOLUTION: What does the Beroe eat? 

PROBLEM: How many er the strong force is due to the exchange of what?

SOLUTION: The strong force is due to the exchange of what?

PROBLEM: How long ago was the Devonian no the Ediacaran period?

SOLUTION:
How long ago was the Ediacaran period?