[Q]: Sentence: Heartwood is often visually distinct from the living sapwood, and can be distinguished in a cross-section where the boundary will tend to follow the growth rings. Question: What simple color distinction can heartwood have that makes it stand out from living wood in a tree?
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[A]: no

[Q]: Sentence: Among the many substances Celtic tribes mined was salt in areas such as Salzburg in Austria where evidence of the Hallstatt culture was found by a mine manager in the 19th century. Question: What did the Celtic tribes mine?
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[A]: yes

[Q]: Sentence: Ibn Sina was even raised to the office of vizier. Question: Ibn Sina left Rey and moved southwards to what city?
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[A]:
no