什么是 reduction?The act or process of reducing.The result of reducing: a reduction in absenteeism. The amount by which something is lessened or diminished: a reduction of 12 percent in violent crime. Biology The first meiotic division, in which the chromosome number is reduced. Also called reduction division.Chemistry A decrease in positive valence or an increase in negative valence by the gaining of electrons.Chemistry A reaction in which hydrogen is combined with a compound.Chemistry A reaction in which oxygen is removed from a compound.Mathematics The canceling of common factors in the numerator and denominator of a fraction.Mathematics The converting of a fraction to its decimal equivalent.Mathematics The converting of an expression or equation to its simplest form.