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

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


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


[Q]: What usually carries description no sediment particles from one place to another?
[A]:
What usually carries sediment particles from one place to another?