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: I have some voice exercises to play the guitar and sing.

A: unacceptable
****
Q: The king of Rock and Roll is more popular than the one of country music.

A: unacceptable
****
Q: Who protected him?

A:
acceptable
****