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".
--------
Question: They widely believed that John was ill.

Answer: acceptable


Question: I doubt you can help me in understanding this.

Answer: acceptable


Question: They can sing.

Answer:
acceptable