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".

They let him go yesterday, he.
unacceptable

Everyone who had been worrying himself stiff said that he was relieved.
acceptable

In general that he understands what's going on is surprising.

unacceptable