"What closed?" or "What did close?" If someone said: "The park closed" and another one heard that something closed but he don't know what it is, what should he use to ask: "What closed?" or "What did close?" ------ I read that we don't need to add a helping verb ("did" in this case) if we ask about the subject, then the correct sentence -according to this rule- would be "What closed?". Am I right ?