[Q]: Sentence: Since the color convention is often undermined or overridden by systems that do not invoke it, it is usually used only in conjunction with other differentiating factors. Question: Some elevators may use the color convention for only what purpose?
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[A]: no

[Q]: Sentence: Before mechanical printing, literature was copied by hand, and many variations were introduced by copyists. Question: Why are there multiple variations of texts before the advent of the printing press?
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[A]: yes

[Q]: Sentence: Hewlett-Packard led "design, creation and management". Question: What company designed this interface?
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[A]:
yes