Q: Sentence (1) I fail to understand your motives.
Sentence (2) A number of banks failed that year.. Word: fail.
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A: different meanings

Q: Sentence (1) The Japanese were active last week on the diplomatic front.
Sentence (2) They advertise on many different fronts.. Word: front.
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A: the same meaning

Q: Sentence (1) The job will take more than an hour.
Sentence (2) I spent an hour at lunch.. Word: hour.
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A:
the same meaning