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".

He kissed her.
acceptable

Every student in Mary's class is working on negative polarity.
acceptable

Little did I know that more trouble was just around the corner.

acceptable