Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.

Ex Input:
Question: Possible Duplicate: What is the correct possessive for nouns ending in s? Before you vote to close as a duplicate, note that these two questions deal with similar issues to this, but none of them address all three criteria of this question: The singular already ends with an s. I am dealing with multiple of the thing. I want the possessive of all of them in general. The singular is class, and the plural is classes. The singular possessive is class's (as addressed here). What is the plural possessive? Is it classes's, or classes'? 
Answer: It is classes', which sounds the same as the singular class's. I would have thought this was a general rule for plural nouns ending -s', -es' or -ies'.

Ex Output:
yes


Ex Input:
Question: In technical literature as well as aircraft user interfaces where there is not enough space to write the whole word, the prefix "trans" is shortened to "x". Transmit -> Xmit Transfer -> Xfer I am interested to know what is the origin of this. I am curious because "Ex" and "Trans" do not have a similar sound. 
Answer: In addition to the other edifying answers and comments: from an information-theory viewpoint, given the rarity of initial "x" in English words, the presence of it (especially if unpronounceable) is a clear signal that there is something at play slightly out of the ordinary, and it will not be easily mistaken for anything else. That is, information-theory-wise, the chance of misunderstanding is low (more technically/precisely, the error-correction properties of this usage are excellent).

Ex Output:
no


Ex Input:
Question: is it 'a usual' or 'an usual'? 'A usual' sounds more correct in my head ('Today was a usual day.') than 'an usual', but u is a vowel. Which one is correct and why? 
Answer: The technical definitions are: open vowel sounds or closed vowel sounds. All open vowel sounds such as, orange, envelope and image require the article "an" to bridge the two open sounds. Closed vowel sounds typically start with an unwritten "yu" consonant such as "a university" or "a united Europe, a Europe which is united" and therefore use the more common "a" article.

Ex Output:

no