You're given a sentence and your task is to classify whether the sentence is acceptable or not. Any sentence which is grammatically correct, has a naturalistic text, is written by a native speaker and which minimizes superfluous content is acceptable, otherwise unacceptable. If the sentence is acceptable then write "acceptable", otherwise "unacceptable".

[Q]: Sam may have been being interrogated by the FBI.
[A]: acceptable


[Q]: John loves his puppy.
[A]: acceptable


[Q]: The harder it has rained, how much faster a flow that appears in the river?
[A]:
unacceptable