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".
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Question: I know which guys you've dated, but I don't know which guys you haven't.

Answer: acceptable


Question: Ellen warned for Helen to come.

Answer: unacceptable


Question: When it rains harder, how much faster a flow that appears in the river?

Answer:
unacceptable