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

[EX Q]: When did What centuries did the Roman times take place within?
[EX A]: What centuries did the Roman times take place within?

[EX Q]: When were ctenophore mnemiopsis leidyi introduced into The Black Sea and the Sea of Azov ahh actually I want to know when were fish larvae accidentally introduced into the Black Sea?
[EX A]: When were fish larvae introduced into the Black Sea accidentally?

[EX Q]: What notion keeps it's meaning through both Newtonian no um Netonian and Schrodinger physics equations?
[EX A]:
What notion keeps it's meaning through both Netonian and Schrodinger physics equations?