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".

Those books slide across the table easily.
acceptable

John gave Mary, and Joan presented to Fred, books which looked.
acceptable

We walked ourselves into a state of exhaustion.

acceptable