Q: Sentence (1) A drop of each sample was analyzed.
Sentence (2) There was a drop in pressure in the pulmonary artery.. Word: drop.
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A: different meanings

Q: Sentence (1) The cover concealed their guns from enemy aircraft.
Sentence (2) They made a cover of a Beatles' song.. Word: cover.
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A: different meanings

Q: Sentence (1) He's just been released from Shadwell nick prison after doing ten years for attempted murder.
Sentence (2) He's in the nick.. Word: nick.
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A:
the same meaning