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".

Jennifer swatted Steve.
acceptable

She speaks enough clearly to be understood.
unacceptable

In the early morning is when I do my best research.

acceptable