A question that is free of any grammatical or logcal errors, should be labeled 'yes', otherwise it should be indicated as 'no'. A question is grammatically correct if all its entities i.e. nouns, verbs, adjectives, prepositions, pronouns, adverbs are at appropriate position. A question is logically correct if the semantic makes sense.

[EX Q]: Sentence: The side of Malaquez's parcel gave way to reveal a greenmunk caught in a sheen of solid air. 
Question: How long was the greenmunk visible?
[EX A]: Yes.

[EX Q]: Sentence: Fossils tell an obscure story of man's slow and sporadic development. 
Question: How often is a new fossil found that is considered really significant to our thinking?
[EX A]: Yes.

[EX Q]: Sentence: At current rates of use, coal will last about 300 years. 
Question: How many days did they take to prepare this report?
[EX A]:
Yes.

