[Q]: Sentence: His explanation was a combination of migration and descent with modification. Question: What was the combination of effects that Darwin considered the most important in determining the differences in species that evolved separately in similar environments?
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[A]: yes

[Q]: Sentence: The first group of people left in February 1805, and by 1808 only about 200 remained, forming a small settlement until the remnants were removed in 1813. Question: When did the first group of people leave Norfolk Island?
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[A]: yes

[Q]: Sentence: Worsening weather forced the two armies to separate: the ships sailed for the safer anchorage of St. Cast, while the army proceeded overland. Question: How did the British army escape
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[A]:
no