Final answer:
The sentence is punctuated correctly.
Step-by-step explanation:
True. The sentence "The kitchen is open until midnight, but the cook quits taking orders an hour before closing" is punctuated correctly. The sentence has a comma before the coordinating conjunction 'but' that connects two closely related independent clauses. The first clause 'The kitchen is open until midnight' and the second clause 'the cook quits taking orders an hour before closing' are both complete sentences and can stand alone.
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