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".

Smith was annealing.
acceptable

With their teacher, the kids have arrived safely, hasn't he?
unacceptable

Sonatas are easy to play on this violin.

acceptable