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

[EX Q]: Which group of Mnemiopsis are hardest to study no sorry which group of ctenophore rather?
[EX A]: Which group of ctenophore are are hardest to study?

[EX Q]: What all is balanced in an open system of particles no sorry what is internally missing from this system?
[EX A]: In an open system of particles, there are no internal what?

[EX Q]: How many people lived in Warsaw oh no no I meant Poland in 1939?
[EX A]:
How many people lived in Poland in 1939?