Detailed Instructions: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
Problem:Possible Duplicate: Is it correct to use 'punctuation outside of the quotations', or 'inside?' I've heard that you should always place ending punctuation inside of quotes, no matter what. Are there any cases where it is appropriate for a sentence to end with '.?.
Solution:
Yes. See the Economist style guide: If the quotation does not include any punctuation, the closing inverted commas should precede any punctuation marks that the sentence requires. More at the Guardian style guide.