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\dfrac{1}{1}=\dfrac{4}{4}=\dfrac{\dfrac{1}{2}}{\dfrac{2}{4}}=\dfrac{100 \, cm }{1 \, m}=\dfrac{1 \, lb }{16 \, oz }=\dfrac{1 \, hr }{60 \, min }=\dfrac{60 \, min }{1 \, hr }