Question: Sentence 1: Head the fish.
Sentence 2: This student heads the class.
Does head mean the same thing in these two sentences?
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Answer: different meanings

Question: Sentence 1: He was responsible for the beginning of negotiations.
Sentence 2: The beginning of the war.
Does beginning mean the same thing in these two sentences?
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Answer: different meanings

Question: Sentence 1: The word is a basic linguistic unit.
Sentence 2: The reduced the number of units and installations.
Does unit mean the same thing in these two sentences?
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Answer:
the same meaning