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.

[Q]: 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.
[A]: yes


[Q]: Question: When someone says I stand corrected. What does that mean? 
Answer: It means "I admit that I was wrong". See e.g. Cambridge Dictionaries: used to admit that something you have said or done was wrong I stand corrected - the date of foundation was 1411, and not 1412 as I had written. Or Wiktionary: Said to acknowledge someone who corrects something that one says or writes that was not correct. The Battle of Hastings was fought in 1056. No it wasn't! Look in the textbook! Oh, sorry. I stand corrected - it was fought in 1066. Note that the Cambridge Dictionary marks this idiom as "formal", and Merriam-Webster's Learner's Dictionary as "somewhat formal".
[A]: yes


[Q]: Question: How can you explain that this double negation is not a double negation? Is there a rule in English about this kind of sentence? PS / Do I have to mention Pink Floyd Copyright ? :-) Edit : Since there are a lot of Pink Floyd related explanation, I'll bring a Freddy Mercury one : "I don't have time for no monkey business", which I also understand as "I don't have time for monkey business". Am I right ? 
Answer: Doubled negatives are often used casually in certain dialects to indicate negative concord, an intensification of negation rather than an inversion of it. This typically happens when both words involved are simple negatives, and is most common with no standing in for a, an, or any alongside don't or ain't. So you can safely assume that He isn't not going to the concert. is double negation proper, because it has emphasis, as is She wasn't unimpressed. because this is litotes, whereas I ain't no hillbilly. is negative concord, because it's obviously casual, and uses ain't no in place of am no or am not a. (It's also a patent lie, but that's beside the point.).
[A]:
yes