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.

Example Input: Question: Somehow I am compelled to use the word "metal" to describe strong "intestinal fortitude", and perseverance however I can't find the spelling or any synonym like this. Does a word that sounds like "metal" exist when describing an individual's character? I'm looking for modern or historic usage of the word. 
Answer: Mettle Defined by Oxford Dictionaries as: a person's ability to cope well with difficulties; spirit and resilience. It is commonly seen in the phrase: (put someone) on their mettle meaning, (of a demanding situation) test someone's ability to face difficulties. 'there were regular public meetings where local MPs were put on their mettle and remorselessly pilloried' Source: ODO Other constructions are possible too, for example: test their mettle, apparently an American version (thanks, @PeterCordes) show your mettle, etc. Origins According to Merriam-Webster, mettle was, as @Sparhawk points out in the comments, originally simply a variant spelling of the word metal (which dates to at least the 13th century), and it was used in all of the same senses as its metallic relative. Over time, however, mettle came to be used mainly in figurative senses referring to the quality of someone's character, with a first known usage in 1581. Today, both words can mean "vigor and strength of spirit or temperament," but only metal is used of metallic substances.
Example Output: yes

Example Input: Question: A friend posed the following word puzzle to me: Can you think of a sentence that keeps the same meaning whether you use "it's" or "its"? He asserted that this puzzle does in fact have a solution. However, it has me completely stumped. I tried to solve an easier problem, to find a sentence which is still grammatical if you change an "its" to "it's", but all I could come up with is examples like "It's light!" (which is, strictly, more of a sentence fragment). What is the solution to the word puzzle? Or, is there some way I can "prove" that the puzzle should have no solution? 
Answer: The following took me about two minutes, so I wouldn't be surprised if it can be improved: "I can never remember what kind of fruit the tree in my garden has - until I look out of the window and see it[']s apples.".
Example Output: yes

Example Input: Question: The word second can refer to ordinal #2 (that which comes after first), or a unit of time, 1/60 of a minute. Ordinarily you might think that this is just a coincidence, but in Spanish, the word segundo also means both a second (of time) and ordinal #2, which suggests that there's some actual link between the two meanings somewhere. So, why is there a "second" of time but not a "first"? 
Answer: The English word minute in the time sense (and the various similar European words) came from Latin 'pars minuta prima' or 'first small part'; when it became necessary to subdivide even further, the obvious term was 'pars minuta secunda' which became second and its various cognates. (Best explained in Etymonline.).
Example Output:
yes